From c2ddc5bfe241879a4b66a5824823ccd05b28dd34 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Mon, 9 Feb 2026 15:29:30 +0100
Subject: [PATCH 01/28] Add attenuation interpolator

---
 src/pg_rad/physics/attenuation.py | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 src/pg_rad/physics/attenuation.py

diff --git a/src/pg_rad/physics/attenuation.py b/src/pg_rad/physics/attenuation.py
new file mode 100644
index 0000000..bdc70e3
--- /dev/null
+++ b/src/pg_rad/physics/attenuation.py
@@ -0,0 +1,15 @@
+from importlib.resources import files
+
+from pandas import read_csv
+from scipy.interpolate import interp1d
+
+
+def get_mass_attenuation_coeff(
+        *args
+        ) -> float:
+    csv = files('pg_rad.data').joinpath('attenuation_table.csv')
+    data = read_csv(csv)
+    x = data["energy_mev"].to_numpy()
+    y = data["mu"].to_numpy()
+    f = interp1d(x, y)
+    return f(*args)

From d4b67be775cc57fc2feac41b06f633388bd4adfd Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Mon, 9 Feb 2026 15:29:46 +0100
Subject: [PATCH 02/28] Add primary photon fluence at distance R from point
 source

---
 src/pg_rad/physics/fluence.py | 37 +++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 src/pg_rad/physics/fluence.py

diff --git a/src/pg_rad/physics/fluence.py b/src/pg_rad/physics/fluence.py
new file mode 100644
index 0000000..8d327ed
--- /dev/null
+++ b/src/pg_rad/physics/fluence.py
@@ -0,0 +1,37 @@
+import numpy as np
+
+
+def phi_single_source(
+        r: float,
+        activity: float | int,
+        branching_ratio: float,
+        mu_mass_air: float,
+        air_density: float,
+        ) -> float:
+    """Compute the contribution of a single point source to the
+    primary photon fluence rate phi at position (x,y,z).
+
+    Args:
+        r (float): [m] Distance to the point source.
+        activity (float | int): [Bq] Activity of the point source.
+        branching_ratio (float): Branching ratio for the photon energy E_gamma.
+        mu_mass_air (float): [cm^2/g] Mass attenuation coefficient for air.
+        air_density (float): [kg/m^3] Air density.
+
+    Returns:
+        phi (float): [s^-1 m^-2] Primary photon fluence rate at distance r from
+        a point source.
+    """
+
+    # Linear photon attenuation coefficient in m^-1.
+    mu_mass_air *= 0.1
+    mu_air = 0.1 * mu_mass_air * air_density
+
+    phi = (
+        activity
+        * branching_ratio
+        * np.exp(-mu_air * r)
+        / (4 * np.pi * r**2)
+    )
+
+    return phi

From 2c436c52ad3d910fa9adaa63cc661335f1a2c1bf Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Mon, 9 Feb 2026 15:30:27 +0100
Subject: [PATCH 03/28] generate init for physics module

---
 src/pg_rad/physics/__init__.py | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 src/pg_rad/physics/__init__.py

diff --git a/src/pg_rad/physics/__init__.py b/src/pg_rad/physics/__init__.py
new file mode 100644
index 0000000..fe9b62d
--- /dev/null
+++ b/src/pg_rad/physics/__init__.py
@@ -0,0 +1,10 @@
+# do not expose internal logger when running mkinit
+__ignore__ = ["logger"]
+from pg_rad.physics import attenuation
+from pg_rad.physics import fluence
+
+from pg_rad.physics.attenuation import (get_mass_attenuation_coeff,)
+from pg_rad.physics.fluence import (phi_single_source,)
+
+__all__ = ['attenuation', 'fluence', 'get_mass_attenuation_coeff',
+           'phi_single_source']

From 0c81b4df899a28ab6f0e2fe6264c819d647ca83c Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Mon, 9 Feb 2026 15:31:53 +0100
Subject: [PATCH 04/28] Add mu_mass_air to isotope automatically calculated
 from energy and fix error msg

---
 src/pg_rad/isotopes/isotope.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/pg_rad/isotopes/isotope.py b/src/pg_rad/isotopes/isotope.py
index ea758b8..78ac54e 100644
--- a/src/pg_rad/isotopes/isotope.py
+++ b/src/pg_rad/isotopes/isotope.py
@@ -1,3 +1,6 @@
+from pg_rad.physics import get_mass_attenuation_coeff
+
+
 class Isotope:
     """Represents the essential information of an isotope.
 
@@ -11,13 +14,14 @@ class Isotope:
             name: str,
             E: float,
             b: float
-    ):        
+    ):
         if E <= 0:
             raise ValueError("primary_gamma must be a positive energy (keV).")
 
         if not (0 <= b <= 1):
-            raise ValueError("branching_ratio_pg must be a ratio (0 <= b <= 1)")
+            raise ValueError("branching_ratio_pg must be a ratio b in [0,1]")
 
         self.name = name
         self.E = E
         self.b = b
+        self.mu_mass_air = get_mass_attenuation_coeff(E / 1000)

From 521e5a556e19b190f3babe2c790b1bee455858d6 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Mon, 9 Feb 2026 15:32:19 +0100
Subject: [PATCH 05/28] Add isotope presets file

---
 src/pg_rad/isotopes/presets.py | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 src/pg_rad/isotopes/presets.py

diff --git a/src/pg_rad/isotopes/presets.py b/src/pg_rad/isotopes/presets.py
new file mode 100644
index 0000000..5b8224b
--- /dev/null
+++ b/src/pg_rad/isotopes/presets.py
@@ -0,0 +1,4 @@
+from .isotope import Isotope
+
+
+CS137 = Isotope("Cs-137", E=661.66, b=0.851)

From d6d9fa6f92ff6d08bfb5ec1992f32bf001f21fcf Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Mon, 9 Feb 2026 15:32:49 +0100
Subject: [PATCH 06/28] update init for isotopes module

---
 src/pg_rad/isotopes/__init__.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/pg_rad/isotopes/__init__.py b/src/pg_rad/isotopes/__init__.py
index 0c7976d..6f000c0 100644
--- a/src/pg_rad/isotopes/__init__.py
+++ b/src/pg_rad/isotopes/__init__.py
@@ -2,7 +2,9 @@
 __ignore__ = ["logger"]
 
 from pg_rad.isotopes import isotope
+from pg_rad.isotopes import presets
 
 from pg_rad.isotopes.isotope import (Isotope,)
+from pg_rad.isotopes.presets import (CS137,)
 
-__all__ = ['Isotope', 'isotope']
+__all__ = ['CS137', 'Isotope', 'isotope', 'presets']

From 2b85a07aa019e0df9c9eefad8dce9c8b579aa1d5 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Mon, 9 Feb 2026 15:34:05 +0100
Subject: [PATCH 07/28] add attenuation table

---
 src/pg_rad/data/__init__.py           |  1 +
 src/pg_rad/data/attenuation_table.csv | 39 +++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)
 create mode 100644 src/pg_rad/data/__init__.py
 create mode 100644 src/pg_rad/data/attenuation_table.csv

diff --git a/src/pg_rad/data/__init__.py b/src/pg_rad/data/__init__.py
new file mode 100644
index 0000000..a9a2c5b
--- /dev/null
+++ b/src/pg_rad/data/__init__.py
@@ -0,0 +1 @@
+__all__ = []
diff --git a/src/pg_rad/data/attenuation_table.csv b/src/pg_rad/data/attenuation_table.csv
new file mode 100644
index 0000000..0c8f024
--- /dev/null
+++ b/src/pg_rad/data/attenuation_table.csv
@@ -0,0 +1,39 @@
+energy_mev,mu
+1.00000E-03,3.606E+03
+1.50000E-03,1.191E+03
+2.00000E-03,5.279E+02
+3.00000E-03,1.625E+02
+3.20290E-03,1.340E+02
+3.20290E-03,1.485E+02
+4.00000E-03,7.788E+01
+5.00000E-03,4.027E+01
+6.00000E-03,2.341E+01
+8.00000E-03,9.921E+00
+1.00000E-02,5.120E+00
+1.50000E-02,1.614E+00
+2.00000E-02,7.779E-01
+3.00000E-02,3.538E-01
+4.00000E-02,2.485E-01
+5.00000E-02,2.080E-01
+6.00000E-02,1.875E-01
+8.00000E-02,1.662E-01
+1.00000E-01,1.541E-01
+1.50000E-01,1.356E-01
+2.00000E-01,1.233E-01
+3.00000E-01,1.067E-01
+4.00000E-01,9.549E-02
+5.00000E-01,8.712E-02
+6.00000E-01,8.055E-02
+8.00000E-01,7.074E-02
+1.00000E+00,6.358E-02
+1.25000E+00,5.687E-02
+1.50000E+00,5.175E-02
+2.00000E+00,4.447E-02
+3.00000E+00,3.581E-02
+4.00000E+00,3.079E-02
+5.00000E+00,2.751E-02
+6.00000E+00,2.522E-02
+8.00000E+00,2.225E-02
+1.00000E+01,2.045E-02
+1.50000E+01,1.810E-02
+2.00000E+01,1.705E-02
\ No newline at end of file

From 016ea6b783dd66deb6d33b0e3f96674645323274 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Mon, 9 Feb 2026 15:35:22 +0100
Subject: [PATCH 08/28] add tests for fluence rate and attenuation
 interpolation

---
 tests/test_attenuation_functions.py | 30 +++++++++++++++++++++
 tests/test_fluence_rate.py          | 41 +++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+)
 create mode 100644 tests/test_attenuation_functions.py
 create mode 100644 tests/test_fluence_rate.py

diff --git a/tests/test_attenuation_functions.py b/tests/test_attenuation_functions.py
new file mode 100644
index 0000000..ad9d5e4
--- /dev/null
+++ b/tests/test_attenuation_functions.py
@@ -0,0 +1,30 @@
+import pytest
+
+from pg_rad.physics import get_mass_attenuation_coeff
+
+
+@pytest.mark.parametrize("energy,mu", [
+    (1.00000E-03, 3.606E+03),
+    (1.00000E-02, 5.120E+00),
+    (1.00000E-01, 1.541E-01),
+    (1.00000E+00, 6.358E-02),
+    (1.00000E+01, 2.045E-02) 
+])
+def test_exact_attenuation_retrieval(energy, mu):
+    """
+    Test if retrieval of values that are exactly in the table is correct.
+    """
+    func_mu = get_mass_attenuation_coeff(energy)
+    assert pytest.approx(func_mu, rel=1E-6) == mu
+
+
+@pytest.mark.parametrize("energy,mu", [
+    (0.662, 0.0778),
+    (1.25, 0.06)
+])
+def test_attenuation_interpolation(energy, mu):
+    """
+    Test Cs-137 and Co-60 mass attenuation coefficients.
+    """
+    interp_mu = get_mass_attenuation_coeff(energy)
+    assert pytest.approx(interp_mu, rel=1E-2) == mu
diff --git a/tests/test_fluence_rate.py b/tests/test_fluence_rate.py
new file mode 100644
index 0000000..710b2fb
--- /dev/null
+++ b/tests/test_fluence_rate.py
@@ -0,0 +1,41 @@
+from math import dist, exp, pi
+
+import pytest
+
+from pg_rad.isotopes import CS137
+from pg_rad.landscape import Landscape
+from pg_rad.objects import PointSource
+
+
+@pytest.fixture
+def phi_ref():
+    A = 100                             # MBq
+    b = 0.851
+    mu_mass_air = 0.0778                # cm^2/g
+    air_density = 1.243                 # kg/m^3
+    r = dist((0, 0, 0), (10, 10, 0))    # m
+
+    A *= 1E9                            # Convert to Bq
+    mu_mass_air *= 0.1                  # Convert to m^2/kg
+
+    mu_air = mu_mass_air * air_density  # [m^2/kg] x [kg/m^3] = [m^-1]
+
+    # [s^-1] x exp([m^-1] x [m]) / [m^-2] = [s^-1 m^-2]
+    phi = A * b * exp(-mu_air * r) / (4 * pi * r**2)
+    return phi
+
+
+@pytest.fixture
+def test_landscape():
+    landscape = Landscape()
+    source = PointSource(
+        pos=(0, 0, 0),
+        activity=100E9,
+        isotope=CS137)
+    landscape.add_sources(source)
+    return landscape
+
+
+def test_single_source_fluence(phi_ref, test_landscape):
+    phi = test_landscape.calculate_fluence_at((10, 10, 0))
+    assert pytest.approx(phi, rel=1E-3) == phi_ref

From a1acf95004e96749c8eb5ac328e1db676261d07c Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Mon, 9 Feb 2026 15:36:23 +0100
Subject: [PATCH 09/28] update sources tests to accomodate new pos attribute

---
 tests/test_sources.py | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/tests/test_sources.py b/tests/test_sources.py
index 156276a..1ce84ee 100644
--- a/tests/test_sources.py
+++ b/tests/test_sources.py
@@ -1,27 +1,36 @@
 import numpy as np
 import pytest
 
-from pg_rad.sources import PointSource
+from pg_rad.objects import PointSource
+from pg_rad.isotopes import Isotope
+
 
 @pytest.fixture
 def test_sources():
+    iso = Isotope("test", E=662, b=0)
     pos_a = np.random.rand(3)
     pos_b = np.random.rand(3)
 
-    a = PointSource(*tuple(pos_a), strength = None)
-    b = PointSource(*tuple(pos_b), strength = None)
+    a = PointSource(pos_a, activity=None, isotope=iso)
+    b = PointSource(pos_b, activity=None, isotope=iso)
 
     return pos_a, pos_b, a, b
 
+
 def test_if_distances_equal(test_sources):
-    """Verify whether from PointSource A to PointSource B is the same as B to A."""
+    """
+    Verify whether distance from PointSource A to B is the same as B to A.
+    """
 
     _, _, a, b = test_sources
 
     assert a.distance_to(b) == b.distance_to(a)
 
+
 def test_distance_calculation(test_sources):
-    """Verify whether distance between two PointSources is calculated correctly."""
+    """
+    Verify whether distance between PointSources is calculated correctly.
+    """
 
     pos_a, pos_b, a, b = test_sources
 
@@ -32,4 +41,4 @@ def test_distance_calculation(test_sources):
     assert np.isclose(
         a.distance_to(b),
         np.sqrt(dx**2 + dy**2 + dz**2),
-        rtol = 1e-12)
\ No newline at end of file
+        rtol=1e-12)

From 9c1b97d912c0ce6365a0e7650857d893ef705fa0 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Tue, 10 Feb 2026 11:24:40 +0100
Subject: [PATCH 10/28] Update sources and objects to new position system

---
 src/pg_rad/objects/objects.py | 36 ++++++++++++++++++++---------------
 src/pg_rad/objects/sources.py | 11 +++--------
 2 files changed, 24 insertions(+), 23 deletions(-)

diff --git a/src/pg_rad/objects/objects.py b/src/pg_rad/objects/objects.py
index 16f03b9..a610d9e 100644
--- a/src/pg_rad/objects/objects.py
+++ b/src/pg_rad/objects/objects.py
@@ -1,36 +1,42 @@
-import math
 from typing import Self
 
+import numpy as np
+
 
 class BaseObject:
     def __init__(
             self,
-            x: float,
-            y: float,
-            z: float,
+            pos: tuple[float, float, float],
             name: str = "Unnamed object",
             color: str = 'grey'):
         """
         A generic object.
 
         Args:
-            x (float): X coordinate.
-            y (float): Y coordinate.
-            z (float): Z coordinate.
+            pos (tuple[float, float, float]): Position vector (x,y,z).
             name (str, optional): Name for the object.
             Defaults to "Unnamed object".
             color (str, optional): Matplotlib compatible color string.
             Defaults to "red".
         """
 
-        self.x = x
-        self.y = y
-        self.z = z
+        if len(pos) != 3:
+            raise ValueError("Position must be tuple of length 3 (x,y,z).")
+        self.pos = pos
         self.name = name
         self.color = color
 
-    def distance_to(self, other: Self) -> float:
-        return math.dist(
-            (self.x, self.y, self.z),
-            (other.x, other.y, other.z),
-        )
+    def distance_to(self, other: Self | tuple) -> float:
+        if isinstance(other, tuple) and len(other) == 3:
+            r = np.linalg.norm(
+                np.subtract(self.pos, other)
+                )
+        else:
+            try:
+                r = np.linalg.norm(
+                    np.subtract(self.pos, other.pos)
+                    )
+            except AttributeError as e:
+                raise e("other must be an object in the world \
+                    or a position tuple (x,y,z).")
+        return r
diff --git a/src/pg_rad/objects/sources.py b/src/pg_rad/objects/sources.py
index 1bc3a2d..ee47509 100644
--- a/src/pg_rad/objects/sources.py
+++ b/src/pg_rad/objects/sources.py
@@ -11,9 +11,7 @@ class PointSource(BaseObject):
 
     def __init__(
             self,
-            x: float,
-            y: float,
-            z: float,
+            pos: tuple,
             activity: int,
             isotope: Isotope,
             name: str | None = None,
@@ -21,9 +19,7 @@ class PointSource(BaseObject):
         """A point source.
 
         Args:
-            x (float): X coordinate.
-            y (float): Y coordinate.
-            z (float): Z coordinate.
+            pos (tuple): a position vector of length 3 (x,y,z).
             activity (int): Activity A in MBq.
             isotope (Isotope): The isotope.
             name (str | None, optional): Can give the source a unique name.
@@ -40,11 +36,10 @@ class PointSource(BaseObject):
         if name is None:
             name = f"Source {self.id}"
 
-        super().__init__(x, y, z, name, color)
+        super().__init__(pos, name, color)
 
         self.activity = activity
         self.isotope = isotope
-        self.color = color
 
         logger.debug(f"Source created: {self.name}")
 

From 0971c2bab94e996179a62d4c2dac4a7f129c28f9 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Tue, 10 Feb 2026 11:28:38 +0100
Subject: [PATCH 11/28] fix typo in unit conversion

---
 src/pg_rad/physics/fluence.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/pg_rad/physics/fluence.py b/src/pg_rad/physics/fluence.py
index 8d327ed..8bae5f3 100644
--- a/src/pg_rad/physics/fluence.py
+++ b/src/pg_rad/physics/fluence.py
@@ -25,7 +25,7 @@ def phi_single_source(
 
     # Linear photon attenuation coefficient in m^-1.
     mu_mass_air *= 0.1
-    mu_air = 0.1 * mu_mass_air * air_density
+    mu_air = mu_mass_air * air_density
 
     phi = (
         activity

From 3f7395ed70d9847504fad1e2c533d28dd8f692d7 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Tue, 10 Feb 2026 13:53:57 +0100
Subject: [PATCH 12/28] add fluence function to landscape and update to new
 position system

---
 src/pg_rad/landscape/landscape.py | 33 ++++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/src/pg_rad/landscape/landscape.py b/src/pg_rad/landscape/landscape.py
index 1883694..815a90d 100644
--- a/src/pg_rad/landscape/landscape.py
+++ b/src/pg_rad/landscape/landscape.py
@@ -3,9 +3,11 @@ import logging
 from matplotlib import pyplot as plt
 from matplotlib.patches import Circle
 import numpy as np
+from numpy.typing import ArrayLike
 
 from pg_rad.path import Path
 from pg_rad.objects import PointSource
+from pg_rad.physics.fluence import phi_single_source
 
 logger = logging.getLogger(__name__)
 
@@ -35,7 +37,6 @@ class Landscape:
 
         self.air_density = air_density
         self.scale = scale
-
         self.path: Path = None
         self.sources: list[PointSource] = []
         logger.debug("Landscape initialized.")
@@ -94,12 +95,10 @@ class Landscape:
             ValueError: If the source is outside the boundaries of the
             landscape.
         """
-        max_x, max_y, max_z = self.world.shape[:3]
-
-        if any(
-            not (0 <= source.x < max_x and
-                 0 <= source.y < max_y and
-                 0 <= source.z < max_z)
+        if not any(
+            (0 <= source.pos[0] <= self.world.shape[0] or
+             0 <= source.pos[1] <= self.world.shape[1] or
+             0 <= source.pos[2] <= self.world.shape[2])
             for source in sources
         ):
             raise ValueError("One or more sources are outside the landscape!")
@@ -110,8 +109,28 @@ class Landscape:
         """
         Set the path in the landscape.
         """
+        if not isinstance(path, Path):
+            raise TypeError("path must be of type Path.")
         self.path = path
 
+    def calculate_fluence_at(self, pos: tuple):
+        total_phi = 0.
+        for source in self.sources:
+            r = source.distance_to(pos)
+            phi_source = phi_single_source(
+                r=r,
+                activity=source.activity,
+                branching_ratio=source.isotope.b,
+                mu_mass_air=source.isotope.mu_mass_air,
+                air_density=self.air_density
+            )
+            total_phi += phi_source
+        return total_phi
+
+    def calculate_fluence_along_path(self):
+        if self.path is None:
+            raise ValueError("Path is not set!")
+
 
 def create_landscape_from_path(path: Path, max_z: float | int = 50):
     """Generate a landscape from a path, using its dimensions to determine

From 6ceffb436126248c0d12e55c1a38c9b445dcc9bd Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Thu, 12 Feb 2026 09:28:37 +0100
Subject: [PATCH 13/28] Move plotting functionality out of Landscape to
 LandscapeSlicePlotter

---
 src/pg_rad/landscape/landscape.py        | 84 +++++++-----------------
 src/pg_rad/plotting/__init__.py          |  7 ++
 src/pg_rad/plotting/landscape_plotter.py | 75 +++++++++++++++++++++
 3 files changed, 105 insertions(+), 61 deletions(-)
 create mode 100644 src/pg_rad/plotting/__init__.py
 create mode 100644 src/pg_rad/plotting/landscape_plotter.py

diff --git a/src/pg_rad/landscape/landscape.py b/src/pg_rad/landscape/landscape.py
index 815a90d..6575087 100644
--- a/src/pg_rad/landscape/landscape.py
+++ b/src/pg_rad/landscape/landscape.py
@@ -13,77 +13,34 @@ logger = logging.getLogger(__name__)
 
 
 class Landscape:
-    """A generic Landscape that can contain a Path and sources.
-
-    Args:
-        air_density (float, optional): Air density, kg/m^3. Defaults to 1.243.
-        size (int | tuple[int, int, int], optional): Size of the world.
-        Defaults to 500.
-        scale (str, optional): The scale of the size argument passed.
-        Defaults to 'meters'.
+    """
+    A generic Landscape that can contain a Path and sources.
     """
     def __init__(
             self,
-            air_density: float = 1.243,
-            size: int | tuple[int, int, int] = 500,
-            scale: str = 'meters'
+            path: Path,
+            point_sources: list[PointSource] = [],
+            size: tuple[int, int, int] = [500, 500, 50],
+            air_density: float = 1.243
             ):
-        if isinstance(size, int):
-            self.world = np.zeros((size, size, size))
-        elif isinstance(size, tuple) and len(size) == 3:
-            self.world = np.zeros(size)
-        else:
-            raise TypeError("size must be integer or a tuple of 3 integers.")
-
-        self.air_density = air_density
-        self.scale = scale
-        self.path: Path = None
-        self.sources: list[PointSource] = []
-        logger.debug("Landscape initialized.")
-
-    def plot(self, z: float | int = 0):
-        """Plot a slice of the world at a height `z`.
+        """Initialize a landscape.
 
         Args:
-            z (int, optional): Height of slice. Defaults to 0.
+            path (Path): A Path object.
+            point_sources (list[PointSource], optional): List of point sources.
+            air_density (float, optional): Air density in kg/m^3. Defaults to 1.243.
+            size (tuple[int, int, int], optional): (x,y,z) dimensions of world in meters. Defaults to [500, 500, 50].
 
-        Returns:
-            fig, ax: Matplotlib figure objects.
+        Raises:
+            TypeError: _description_
         """
-        x_lim, y_lim, _ = self.world.shape
 
-        fig, ax = plt.subplots()
-        ax.set_xlim(right=x_lim)
-        ax.set_ylim(top=y_lim)
-        ax.set_xlabel(f"X [{self.scale}]")
-        ax.set_ylabel(f"Y [{self.scale}]")
+        self.path = path
+        self.point_sources = point_sources
+        self.size = size
+        self.air_density = air_density
 
-        if self.path is not None:
-            ax.plot(self.path.x_list, self.path.y_list, 'bo-')
-
-        for s in self.sources:
-            if np.isclose(s.z, z):
-                dot = Circle(
-                        (s.x, s.y),
-                        radius=5,
-                        color=s.color,
-                        zorder=5
-                )
-
-                ax.text(
-                    s.x + 0.06,
-                    s.y + 0.06,
-                    s.name,
-                    color=s.color,
-                    fontsize=10,
-                    ha="left",
-                    va="bottom",
-                    zorder=6
-                )
-
-                ax.add_patch(dot)
-
-        return fig, ax
+        logger.debug("Landscape initialized.")
 
     def add_sources(self, *sources: PointSource):
         """Add one or more point sources to the world.
@@ -150,3 +107,8 @@ def create_landscape_from_path(path: Path, max_z: float | int = 50):
     landscape = Landscape(size=(max_x, max_y, max_z))
     landscape.path = path
     return landscape
+
+
+class LandscapeBuilder:
+    def __init__(self):
+        pass
\ No newline at end of file
diff --git a/src/pg_rad/plotting/__init__.py b/src/pg_rad/plotting/__init__.py
new file mode 100644
index 0000000..271d2c9
--- /dev/null
+++ b/src/pg_rad/plotting/__init__.py
@@ -0,0 +1,7 @@
+# do not expose internal logger when running mkinit
+__ignore__ = ["logger"]
+from pg_rad.plotting import landscape_plotter
+
+from pg_rad.plotting.landscape_plotter import (LandscapeSlicePlotter,)
+
+__all__ = ['LandscapeSlicePlotter', 'landscape_plotter']
diff --git a/src/pg_rad/plotting/landscape_plotter.py b/src/pg_rad/plotting/landscape_plotter.py
new file mode 100644
index 0000000..9c5552b
--- /dev/null
+++ b/src/pg_rad/plotting/landscape_plotter.py
@@ -0,0 +1,75 @@
+import logging
+
+from matplotlib import pyplot as plt
+from matplotlib.patches import Circle
+
+from pg_rad.landscape import Landscape
+
+
+logger = logging.getLogger(__name__)
+
+
+class LandscapeSlicePlotter:
+    def plot(self, landscape: Landscape, z: int = 0):
+        """Plot a top-down slice of the landscape at a height z.
+
+        Args:
+            landscape (Landscape): the landscape to plot
+            z (int, optional): Height at which to plot slice. Defaults to 0.
+        """        """
+
+        """
+        self.z = z
+        fig, ax = plt.subplots()
+
+        self._draw_base(ax, landscape)
+        self._draw_path(ax, landscape)
+        self._draw_point_sources(ax, landscape)
+
+        ax.set_aspect("equal")
+        plt.show()
+
+    def _draw_base(self, ax, landscape):
+        width, height = landscape.size[:2]
+        ax.set_xlim(right=width)
+        ax.set_ylim(top=height)
+        ax.set_xlabel("X [m]")
+        ax.set_ylabel("Y [m]")
+        ax.set_title(f"Landscape (top-down, z = {self.z})")
+
+    def _draw_path(self, ax, landscape):
+        if landscape.path.z < self.z:
+            ax.plot(landscape.path.x_list, landscape.path.y_list, 'bo-')
+        else:
+            logger.warning(
+                "Path is above the slice height z."
+                "It will not show on the plot."
+                )
+
+    def _draw_point_sources(self, ax, landscape):
+        for s in landscape.point_sources:
+            if s.z <= self.z:
+                dot = Circle(
+                        (s.x, s.y),
+                        radius=5,
+                        color=s.color,
+                        zorder=5
+                )
+
+                ax.text(
+                    s.x + 0.06,
+                    s.y + 0.06,
+                    s.name,
+                    color=s.color,
+                    fontsize=10,
+                    ha="left",
+                    va="bottom",
+                    zorder=6
+                )
+
+                ax.add_patch(dot)
+            else:
+                logger.warning(
+                    f"Source {s.name} is above slice height z."
+                    "It will not show on the plot."
+                    )

From 4f72fe8ff488989b220afcada2738a0f289aab33 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Thu, 12 Feb 2026 14:02:13 +0100
Subject: [PATCH 14/28] Add OutOfBoundsError

---
 src/pg_rad/exceptions/__init__.py   | 4 ++--
 src/pg_rad/exceptions/exceptions.py | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/pg_rad/exceptions/__init__.py b/src/pg_rad/exceptions/__init__.py
index 426b7e7..99b24a1 100644
--- a/src/pg_rad/exceptions/__init__.py
+++ b/src/pg_rad/exceptions/__init__.py
@@ -4,7 +4,7 @@ __ignore__ = ["logger"]
 from pg_rad.exceptions import exceptions
 
 from pg_rad.exceptions.exceptions import (ConvergenceError, DataLoadError,
-                                          InvalidCSVError,)
+                                          InvalidCSVError, OutOfBoundsError,)
 
 __all__ = ['ConvergenceError', 'DataLoadError', 'InvalidCSVError',
-           'exceptions']
+           'OutOfBoundsError', 'exceptions']
diff --git a/src/pg_rad/exceptions/exceptions.py b/src/pg_rad/exceptions/exceptions.py
index 60a1b34..dc8c3eb 100644
--- a/src/pg_rad/exceptions/exceptions.py
+++ b/src/pg_rad/exceptions/exceptions.py
@@ -8,3 +8,7 @@ class DataLoadError(Exception):
 
 class InvalidCSVError(DataLoadError):
     """Raised when a file is not a valid CSV."""
+
+
+class OutOfBoundsError(Exception):
+    """Raised when an object is attempted to be placed out of bounds."""

From 8274b5e37191056d5a015ee14f9892c3f9875d40 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Thu, 12 Feb 2026 14:41:05 +0100
Subject: [PATCH 15/28] add size of path as attribute to Path

---
 src/pg_rad/path/path.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/pg_rad/path/path.py b/src/pg_rad/path/path.py
index e750ba2..dca2582 100644
--- a/src/pg_rad/path/path.py
+++ b/src/pg_rad/path/path.py
@@ -70,6 +70,11 @@ class Path:
             ]
 
         self.z = z
+        self.size = (
+            np.ceil(max(self.x_list)),
+            np.ceil(max(self.y_list)),
+            z
+        )
 
         logger.debug("Path created.")
 

From a95cca26d928823fa80562ff05ffa2e701527a19 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Thu, 12 Feb 2026 14:43:41 +0100
Subject: [PATCH 16/28] Move landscape construction to LandscapeBuilder object

---
 src/pg_rad/landscape/__init__.py  |   4 +-
 src/pg_rad/landscape/landscape.py | 154 ++++++++++++++++++------------
 2 files changed, 97 insertions(+), 61 deletions(-)

diff --git a/src/pg_rad/landscape/__init__.py b/src/pg_rad/landscape/__init__.py
index 9a0c85c..5bfc4d7 100644
--- a/src/pg_rad/landscape/__init__.py
+++ b/src/pg_rad/landscape/__init__.py
@@ -3,6 +3,6 @@ __ignore__ = ["logger"]
 
 from pg_rad.landscape import landscape
 
-from pg_rad.landscape.landscape import (Landscape, create_landscape_from_path,)
+from pg_rad.landscape.landscape import (Landscape, LandscapeBuilder,)
 
-__all__ = ['Landscape', 'create_landscape_from_path', 'landscape']
+__all__ = ['Landscape', 'LandscapeBuilder', 'landscape']
diff --git a/src/pg_rad/landscape/landscape.py b/src/pg_rad/landscape/landscape.py
index 6575087..861f9f2 100644
--- a/src/pg_rad/landscape/landscape.py
+++ b/src/pg_rad/landscape/landscape.py
@@ -1,12 +1,10 @@
 import logging
+from typing import Self
 
-from matplotlib import pyplot as plt
-from matplotlib.patches import Circle
-import numpy as np
-from numpy.typing import ArrayLike
-
-from pg_rad.path import Path
+from pg_rad.dataloader import load_data
+from pg_rad.exceptions import OutOfBoundsError
 from pg_rad.objects import PointSource
+from pg_rad.path import Path, path_from_RT90
 from pg_rad.physics.fluence import phi_single_source
 
 logger = logging.getLogger(__name__)
@@ -28,8 +26,10 @@ class Landscape:
         Args:
             path (Path): A Path object.
             point_sources (list[PointSource], optional): List of point sources.
-            air_density (float, optional): Air density in kg/m^3. Defaults to 1.243.
-            size (tuple[int, int, int], optional): (x,y,z) dimensions of world in meters. Defaults to [500, 500, 50].
+            air_density (float, optional): Air density in kg/m^3.
+                Defaults to 1.243.
+            size (tuple[int, int, int], optional): (x,y,z) dimensions of world
+                in meters. Defaults to [500, 500, 50].
 
         Raises:
             TypeError: _description_
@@ -42,34 +42,6 @@ class Landscape:
 
         logger.debug("Landscape initialized.")
 
-    def add_sources(self, *sources: PointSource):
-        """Add one or more point sources to the world.
-
-        Args:
-            *sources (pg_rad.sources.PointSource): One or more sources,
-            passed as Source1, Source2, ...
-        Raises:
-            ValueError: If the source is outside the boundaries of the
-            landscape.
-        """
-        if not any(
-            (0 <= source.pos[0] <= self.world.shape[0] or
-             0 <= source.pos[1] <= self.world.shape[1] or
-             0 <= source.pos[2] <= self.world.shape[2])
-            for source in sources
-        ):
-            raise ValueError("One or more sources are outside the landscape!")
-
-        self.sources.extend(sources)
-
-    def set_path(self, path: Path):
-        """
-        Set the path in the landscape.
-        """
-        if not isinstance(path, Path):
-            raise TypeError("path must be of type Path.")
-        self.path = path
-
     def calculate_fluence_at(self, pos: tuple):
         total_phi = 0.
         for source in self.sources:
@@ -85,30 +57,94 @@ class Landscape:
         return total_phi
 
     def calculate_fluence_along_path(self):
-        if self.path is None:
-            raise ValueError("Path is not set!")
-
-
-def create_landscape_from_path(path: Path, max_z: float | int = 50):
-    """Generate a landscape from a path, using its dimensions to determine
-    the size of the landscape.
-
-    Args:
-        path (Path): A Path object describing the trajectory.
-        max_z (int, optional): Height of the world. Defaults to 50 meters.
-
-    Returns:
-        landscape (pg_rad.landscape.Landscape): A landscape with dimensions
-        based on the provided Path.
-    """
-    max_x = np.ceil(max(path.x_list))
-    max_y = np.ceil(max(path.y_list))
-
-    landscape = Landscape(size=(max_x, max_y, max_z))
-    landscape.path = path
-    return landscape
+        pass
 
 
 class LandscapeBuilder:
     def __init__(self):
-        pass
\ No newline at end of file
+        self._path = None
+        self._point_sources = []
+        self._size = None
+        self._air_density = None
+
+    def set_air_density(self, air_density) -> Self:
+        """Set the air density of the world."""
+        self._air_density = air_density
+        return self
+
+    def set_landscape_size(self, size: tuple[int, int, int]) -> Self:
+        """Set the size of the landscape in meters (x,y,z)."""
+        if self._path and any(p > s for p, s in zip(self._path.size, size)):
+            raise OutOfBoundsError(
+                "Cannot set landscape size smaller than the path."
+            )
+
+        self._size = size
+        logger.debug("Size of the landscape has been updated.")
+
+        return self
+
+    def set_path_from_experimental_data(
+        self,
+        filename: str,
+        z: int,
+        east_col: str = "East",
+        north_col: str = "North"
+    ) -> Self:
+        df = load_data(filename)
+        self._path = path_from_RT90(
+            df=df,
+            east_col=east_col,
+            north_col=north_col
+        )
+
+        # The size of the landscape will be updated if
+        # 1) _size is not set, or
+        # 2) _size is too small to contain the path.
+        needs_resize = (
+            not self._size
+            or any(p > s for p, s in zip(self._path.size, self._size))
+        )
+
+        if needs_resize:
+            if not self._size:
+                logger.info("Landscape size set to path dimensions.")
+            else:
+                logger.warning(
+                    "Path exceeds current landscape size. "
+                    "Expanding landscape to accommodate it."
+                )
+
+            self.set_landscape_size(self._path.size)
+
+        return self
+
+    def set_point_sources(self, *sources):
+        """Add one or more point sources to the world.
+
+        Args:
+            *sources (pg_rad.sources.PointSource): One or more sources,
+            passed as Source1, Source2, ...
+        Raises:
+            OutOfBoundsError: If any source is outside the boundaries of the
+            landscape.
+        """
+
+        if any(
+            any(p < 0 or p >= s for p, s in zip(source.pos, self._size))
+            for source in sources
+        ):
+            raise OutOfBoundsError(
+                "One or more sources attempted to "
+                "be placed outside the landscape."
+                )
+
+        self._point_sources = sources
+
+    def build(self):
+        return Landscape(
+            path=self._path,
+            point_sources=self._point_sources,
+            size=self._size,
+            air_density=self._air_density
+        )

From abc1195c917bbcd437151704762383cc43d05b7c Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Thu, 12 Feb 2026 14:45:24 +0100
Subject: [PATCH 17/28] Rewrite preset isotope

---
 src/pg_rad/isotopes/presets.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/pg_rad/isotopes/presets.py b/src/pg_rad/isotopes/presets.py
index 5b8224b..9d07a65 100644
--- a/src/pg_rad/isotopes/presets.py
+++ b/src/pg_rad/isotopes/presets.py
@@ -1,4 +1,10 @@
 from .isotope import Isotope
 
 
-CS137 = Isotope("Cs-137", E=661.66, b=0.851)
+class CS137(Isotope):
+    def __init__(self):
+        super.__init__(
+            name="Cs-137",
+            E=661.66,
+            b=0.851
+        )

From 82331f3bbd75e49c4c3ad79eb868226ddfc0ef84 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Thu, 12 Feb 2026 16:48:16 +0100
Subject: [PATCH 18/28] add default value for object position (0,0,0)

---
 src/pg_rad/objects/objects.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/pg_rad/objects/objects.py b/src/pg_rad/objects/objects.py
index a610d9e..d3ec285 100644
--- a/src/pg_rad/objects/objects.py
+++ b/src/pg_rad/objects/objects.py
@@ -6,7 +6,7 @@ import numpy as np
 class BaseObject:
     def __init__(
             self,
-            pos: tuple[float, float, float],
+            pos: tuple[float, float, float] = (0, 0, 0),
             name: str = "Unnamed object",
             color: str = 'grey'):
         """

From 55258d772771542e70fb250ff8e36976923a797f Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Fri, 13 Feb 2026 14:46:51 +0100
Subject: [PATCH 19/28] rename pg_rad logging->logger to avoid import conflict
 with default logging library.

---
 src/pg_rad/logger/__init__.py            | 5 +++++
 src/pg_rad/{logging => logger}/logger.py | 9 +++++----
 src/pg_rad/logging/__init__.py           | 5 -----
 3 files changed, 10 insertions(+), 9 deletions(-)
 create mode 100644 src/pg_rad/logger/__init__.py
 rename src/pg_rad/{logging => logger}/logger.py (67%)
 delete mode 100644 src/pg_rad/logging/__init__.py

diff --git a/src/pg_rad/logger/__init__.py b/src/pg_rad/logger/__init__.py
new file mode 100644
index 0000000..57b4e3f
--- /dev/null
+++ b/src/pg_rad/logger/__init__.py
@@ -0,0 +1,5 @@
+from pg_rad.logger import logger
+
+from pg_rad.logger.logger import (setup_logger,)
+
+__all__ = ['logger', 'setup_logger']
diff --git a/src/pg_rad/logging/logger.py b/src/pg_rad/logger/logger.py
similarity index 67%
rename from src/pg_rad/logging/logger.py
rename to src/pg_rad/logger/logger.py
index a460e20..370f35f 100644
--- a/src/pg_rad/logging/logger.py
+++ b/src/pg_rad/logger/logger.py
@@ -1,8 +1,10 @@
-import logging
-import pathlib
+import logging.config
+from importlib.resources import files
 
 import yaml
 
+from pg_rad.configs.filepaths import LOGGING_CONFIG
+
 
 def setup_logger(log_level: str = "WARNING"):
     levels = ["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"]
@@ -10,8 +12,7 @@ def setup_logger(log_level: str = "WARNING"):
     if log_level not in levels:
         raise ValueError(f"Log level must be one of {levels}.")
 
-    base_dir = pathlib.Path(__file__).resolve().parent
-    config_file = base_dir / "configs" / "logging.yml"
+    config_file = files('pg_rad.configs').joinpath(LOGGING_CONFIG)
 
     with open(config_file) as f:
         config = yaml.safe_load(f)
diff --git a/src/pg_rad/logging/__init__.py b/src/pg_rad/logging/__init__.py
deleted file mode 100644
index 666f5de..0000000
--- a/src/pg_rad/logging/__init__.py
+++ /dev/null
@@ -1,5 +0,0 @@
-from pg_rad.logging import logger
-
-from pg_rad.logging.logger import (setup_logger,)
-
-__all__ = ['logger', 'setup_logger']

From 26f96b06fe3001777aee0e008dfb10cd28423e9b Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Fri, 13 Feb 2026 14:50:02 +0100
Subject: [PATCH 20/28] code file paths/names in config folder for more
 centralized definition of filenames

---
 src/pg_rad/configs/filepaths.py                               | 3 +++
 .../coordinates.csv => src/pg_rad/data/test_path_coords.csv   | 0
 src/pg_rad/physics/attenuation.py                             | 4 +++-
 3 files changed, 6 insertions(+), 1 deletion(-)
 create mode 100644 src/pg_rad/configs/filepaths.py
 rename tests/data/coordinates.csv => src/pg_rad/data/test_path_coords.csv (100%)

diff --git a/src/pg_rad/configs/filepaths.py b/src/pg_rad/configs/filepaths.py
new file mode 100644
index 0000000..e8103af
--- /dev/null
+++ b/src/pg_rad/configs/filepaths.py
@@ -0,0 +1,3 @@
+ATTENUATION_TABLE = 'attenuation_table.csv'
+TEST_EXP_DATA = 'test_path_coords.csv'
+LOGGING_CONFIG = 'logging.yml'
diff --git a/tests/data/coordinates.csv b/src/pg_rad/data/test_path_coords.csv
similarity index 100%
rename from tests/data/coordinates.csv
rename to src/pg_rad/data/test_path_coords.csv
diff --git a/src/pg_rad/physics/attenuation.py b/src/pg_rad/physics/attenuation.py
index bdc70e3..9af70e9 100644
--- a/src/pg_rad/physics/attenuation.py
+++ b/src/pg_rad/physics/attenuation.py
@@ -3,11 +3,13 @@ from importlib.resources import files
 from pandas import read_csv
 from scipy.interpolate import interp1d
 
+from pg_rad.configs.filepaths import ATTENUATION_TABLE
+
 
 def get_mass_attenuation_coeff(
         *args
         ) -> float:
-    csv = files('pg_rad.data').joinpath('attenuation_table.csv')
+    csv = files('pg_rad.data').joinpath(ATTENUATION_TABLE)
     data = read_csv(csv)
     x = data["energy_mev"].to_numpy()
     y = data["mu"].to_numpy()

From 49a0dcd3012267d69c83a8b038690ffa5bc76c1c Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Fri, 13 Feb 2026 14:55:42 +0100
Subject: [PATCH 21/28] Improve isotopes and sources

---
 src/pg_rad/isotopes/presets.py |  2 +-
 src/pg_rad/objects/sources.py  | 17 +++++++++--------
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/src/pg_rad/isotopes/presets.py b/src/pg_rad/isotopes/presets.py
index 9d07a65..d8135d6 100644
--- a/src/pg_rad/isotopes/presets.py
+++ b/src/pg_rad/isotopes/presets.py
@@ -3,7 +3,7 @@ from .isotope import Isotope
 
 class CS137(Isotope):
     def __init__(self):
-        super.__init__(
+        super().__init__(
             name="Cs-137",
             E=661.66,
             b=0.851
diff --git a/src/pg_rad/objects/sources.py b/src/pg_rad/objects/sources.py
index ee47509..9361f1f 100644
--- a/src/pg_rad/objects/sources.py
+++ b/src/pg_rad/objects/sources.py
@@ -11,22 +11,23 @@ class PointSource(BaseObject):
 
     def __init__(
             self,
-            pos: tuple,
             activity: int,
             isotope: Isotope,
+            pos: tuple[float, float, float] = (0, 0, 0),
             name: str | None = None,
-            color: str = "red"):
+            color: str = 'red'
+            ):
         """A point source.
 
         Args:
-            pos (tuple): a position vector of length 3 (x,y,z).
             activity (int): Activity A in MBq.
             isotope (Isotope): The isotope.
-            name (str | None, optional): Can give the source a unique name.
-            Defaults to None, making the name sequential.
-            (Source-1, Source-2, etc.).
-            color (str, optional): Matplotlib compatible color string.
-            Defaults to "red".
+            pos (tuple[float, float, float], optional):
+                Position of the PointSource.
+            name (str, optional): Can give the source a unique name.
+                If not provided, point sources are sequentially
+                named: Source1, Source2, ...
+            color (str, optional): Matplotlib compatible color string
         """
 
         self.id = PointSource._id_counter

From e8bf6875634a022fe74cdec3169bd3bfcc58daea Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Fri, 13 Feb 2026 14:56:27 +0100
Subject: [PATCH 22/28] add default box height to ensure non-zero z dimension
 in the landscape

---
 src/pg_rad/path/path.py | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/pg_rad/path/path.py b/src/pg_rad/path/path.py
index dca2582..5c9ade3 100644
--- a/src/pg_rad/path/path.py
+++ b/src/pg_rad/path/path.py
@@ -42,14 +42,18 @@ class Path:
     def __init__(
             self,
             coord_list: Sequence[tuple[float, float]],
-            z: float = 0
+            z: float = 0.,
+            z_box: float = 50.
                  ):
         """Construct a path of sequences based on a list of coordinates.
 
         Args:
             coord_list (Sequence[tuple[float, float]]): List of x,y
             coordinates.
-            z (float, optional): Height of the path. Defaults to 0.
+            z (float, optional): position of the path in z-direction in meters.
+                Defaults to 0 meters.
+            z_box (float, optional): How much empty space to set
+                above the path in meters. Defaults to 50 meters.
         """
 
         if len(coord_list) < 2:
@@ -73,7 +77,7 @@ class Path:
         self.size = (
             np.ceil(max(self.x_list)),
             np.ceil(max(self.y_list)),
-            z
+            z + z_box
         )
 
         logger.debug("Path created.")

From a4fb4a7c5768daa1e9621ade9307fb6ea61db169 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Fri, 13 Feb 2026 14:57:37 +0100
Subject: [PATCH 23/28] Add LandscapeDirector with a test case to build
 landscape using LandscapeBuilder

---
 src/pg_rad/landscape/__init__.py  |  5 ++++-
 src/pg_rad/landscape/director.py  | 23 +++++++++++++++++++++++
 src/pg_rad/landscape/landscape.py | 23 +++++++++++++++++------
 3 files changed, 44 insertions(+), 7 deletions(-)
 create mode 100644 src/pg_rad/landscape/director.py

diff --git a/src/pg_rad/landscape/__init__.py b/src/pg_rad/landscape/__init__.py
index 5bfc4d7..9dda6f9 100644
--- a/src/pg_rad/landscape/__init__.py
+++ b/src/pg_rad/landscape/__init__.py
@@ -1,8 +1,11 @@
 # do not expose internal logger when running mkinit
 __ignore__ = ["logger"]
 
+from pg_rad.landscape import director
 from pg_rad.landscape import landscape
 
+from pg_rad.landscape.director import (LandscapeDirector,)
 from pg_rad.landscape.landscape import (Landscape, LandscapeBuilder,)
 
-__all__ = ['Landscape', 'LandscapeBuilder', 'landscape']
+__all__ = ['Landscape', 'LandscapeBuilder', 'LandscapeDirector', 'director',
+           'landscape']
diff --git a/src/pg_rad/landscape/director.py b/src/pg_rad/landscape/director.py
new file mode 100644
index 0000000..e1fd9f4
--- /dev/null
+++ b/src/pg_rad/landscape/director.py
@@ -0,0 +1,23 @@
+from importlib.resources import files
+import logging
+
+from pg_rad.configs.filepaths import TEST_EXP_DATA
+from pg_rad.isotopes import CS137
+from pg_rad.landscape.landscape import LandscapeBuilder
+from pg_rad.objects import PointSource
+
+
+class LandscapeDirector:
+    def __init__(self):
+        self.logger = logging.getLogger(__name__)
+        self.logger.debug("LandscapeDirector initialized.")
+
+    def build_test_landscape(self):
+        fp = files('pg_rad.data').joinpath(TEST_EXP_DATA)
+        source = PointSource(activity=100, isotope=CS137(), pos=(0, 0, 0))
+        lb = LandscapeBuilder("Test landscape")
+        lb.set_air_density(1.243)
+        lb.set_path_from_experimental_data(fp, z=0)
+        lb.set_point_sources(source)
+        landscape = lb.build()
+        return landscape
diff --git a/src/pg_rad/landscape/landscape.py b/src/pg_rad/landscape/landscape.py
index 861f9f2..a0e58d5 100644
--- a/src/pg_rad/landscape/landscape.py
+++ b/src/pg_rad/landscape/landscape.py
@@ -16,6 +16,7 @@ class Landscape:
     """
     def __init__(
             self,
+            name: str,
             path: Path,
             point_sources: list[PointSource] = [],
             size: tuple[int, int, int] = [500, 500, 50],
@@ -35,12 +36,13 @@ class Landscape:
             TypeError: _description_
         """
 
+        self.name = name
         self.path = path
         self.point_sources = point_sources
         self.size = size
         self.air_density = air_density
 
-        logger.debug("Landscape initialized.")
+        logger.debug(f"Landscape created: {self.name}")
 
     def calculate_fluence_at(self, pos: tuple):
         total_phi = 0.
@@ -61,12 +63,15 @@ class Landscape:
 
 
 class LandscapeBuilder:
-    def __init__(self):
+    def __init__(self, name: str = "Unnamed landscape"):
+        self.name = name
         self._path = None
         self._point_sources = []
         self._size = None
         self._air_density = None
 
+        logger.debug(f"LandscapeBuilder initialized: {self.name}")
+
     def set_air_density(self, air_density) -> Self:
         """Set the air density of the world."""
         self._air_density = air_density
@@ -95,7 +100,8 @@ class LandscapeBuilder:
         self._path = path_from_RT90(
             df=df,
             east_col=east_col,
-            north_col=north_col
+            north_col=north_col,
+            z=z
         )
 
         # The size of the landscape will be updated if
@@ -108,11 +114,12 @@ class LandscapeBuilder:
 
         if needs_resize:
             if not self._size:
-                logger.info("Landscape size set to path dimensions.")
+                logger.debug("Because no Landscape size was set, "
+                             "it will now set to path dimensions.")
             else:
                 logger.warning(
                     "Path exceeds current landscape size. "
-                    "Expanding landscape to accommodate it."
+                    "Landscape size will be expanded to accommodate path."
                 )
 
             self.set_landscape_size(self._path.size)
@@ -142,9 +149,13 @@ class LandscapeBuilder:
         self._point_sources = sources
 
     def build(self):
-        return Landscape(
+        landscape = Landscape(
+            name=self.name,
             path=self._path,
             point_sources=self._point_sources,
             size=self._size,
             air_density=self._air_density
         )
+
+        logger.info(f"Landscape built successfully: {landscape.name}")
+        return landscape

From ac8c38592da00562b353390637311870f9095760 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Fri, 13 Feb 2026 14:58:11 +0100
Subject: [PATCH 24/28] Add CLI entry point with --test flag for building test
 landscape using LandscapeDirector

---
 src/pg_rad/main.py | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 src/pg_rad/main.py

diff --git a/src/pg_rad/main.py b/src/pg_rad/main.py
new file mode 100644
index 0000000..19f4161
--- /dev/null
+++ b/src/pg_rad/main.py
@@ -0,0 +1,33 @@
+import argparse
+
+from pg_rad.logger import setup_logger
+from pg_rad.landscape import LandscapeDirector
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        prog="pg-rad",
+        description="Primary Gamma RADiation landscape tool"
+    )
+
+    parser.add_argument(
+        "--test",
+        action="store_true",
+        help="Load and run the test landscape"
+    )
+    parser.add_argument(
+        "--loglevel",
+        default="INFO",
+        choices=["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"],
+    )
+
+    args = parser.parse_args()
+    setup_logger(args.loglevel)
+
+    if args.test:
+        landscape = LandscapeDirector().build_test_landscape()
+        print(landscape.name)
+
+
+if __name__ == "__main__":
+    main()

From 845f006cd387d2ddd48f85af9f9ab2e8958b2efb Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Fri, 13 Feb 2026 15:02:53 +0100
Subject: [PATCH 25/28] Update pyproject.toml and README.md to reflect new
 conditions.

---
 README.md      | 8 ++++++++
 pyproject.toml | 4 ++++
 2 files changed, 12 insertions(+)

diff --git a/README.md b/README.md
index d3a79ea..3b78136 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,14 @@ With the virtual environment activated, run:
 pip install -e .[dev]
 ```
 
+## Running example landscape
+
+The example landscape can be generated using the command-line interface. Still in the virtual environment, run
+
+```
+pgrad --test --loglevel DEBUG
+```
+
 ## Tests
 
 Tests can be run with `pytest` from the root directory of the repository. With the virtual environment activated, run:
diff --git a/pyproject.toml b/pyproject.toml
index 0f82ac2..07d3d1f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,6 +7,7 @@ where = ["src"]
 
 [tool.setuptools.package-data]
 "pg_rad.data" = ["*.csv"]
+"pg_rad.configs" = ["*.yml"]
 
 [project]
 name = "pg-rad"
@@ -26,6 +27,9 @@ dependencies = [
 license = "MIT"
 license-files = ["LICEN[CS]E*"]
 
+[project.scripts]
+pgrad = "pg_rad.main:main"
+
 [project.urls]
 Homepage = "https://github.com/pim-n/pg-rad"
 Issues = "https://github.com/pim-n/pg-rad/issues"

From 0db1fe062638c48d737f7ee11ef5eaefebbae220 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Fri, 13 Feb 2026 16:01:07 +0100
Subject: [PATCH 26/28] manually remove detector imports (not implemented yet)

---
 src/pg_rad/objects/__init__.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/pg_rad/objects/__init__.py b/src/pg_rad/objects/__init__.py
index 2170a46..92edc21 100644
--- a/src/pg_rad/objects/__init__.py
+++ b/src/pg_rad/objects/__init__.py
@@ -1,13 +1,11 @@
 # do not expose internal logger when running mkinit
 __ignore__ = ["logger"]
 
-from pg_rad.objects import detectors
 from pg_rad.objects import objects
 from pg_rad.objects import sources
 
-from pg_rad.objects.detectors import (Detector,)
 from pg_rad.objects.objects import (BaseObject,)
 from pg_rad.objects.sources import (PointSource,)
 
-__all__ = ['BaseObject', 'Detector', 'PointSource', 'detectors', 'objects',
+__all__ = ['BaseObject', 'PointSource', 'objects',
            'sources']

From beb411d456e5ee03843e775e9bb595af2620870e Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Fri, 13 Feb 2026 16:07:42 +0100
Subject: [PATCH 27/28] update tests to reflect new Landscape design

---
 src/pg_rad/landscape/director.py    |  2 +-
 src/pg_rad/landscape/landscape.py   |  2 +-
 tests/test_attenuation_functions.py |  5 ++---
 tests/test_fluence_rate.py          | 11 ++---------
 tests/test_sources.py               |  8 ++++----
 5 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/src/pg_rad/landscape/director.py b/src/pg_rad/landscape/director.py
index e1fd9f4..edddd7f 100644
--- a/src/pg_rad/landscape/director.py
+++ b/src/pg_rad/landscape/director.py
@@ -14,7 +14,7 @@ class LandscapeDirector:
 
     def build_test_landscape(self):
         fp = files('pg_rad.data').joinpath(TEST_EXP_DATA)
-        source = PointSource(activity=100, isotope=CS137(), pos=(0, 0, 0))
+        source = PointSource(activity=100E9, isotope=CS137(), pos=(0, 0, 0))
         lb = LandscapeBuilder("Test landscape")
         lb.set_air_density(1.243)
         lb.set_path_from_experimental_data(fp, z=0)
diff --git a/src/pg_rad/landscape/landscape.py b/src/pg_rad/landscape/landscape.py
index a0e58d5..805081e 100644
--- a/src/pg_rad/landscape/landscape.py
+++ b/src/pg_rad/landscape/landscape.py
@@ -46,7 +46,7 @@ class Landscape:
 
     def calculate_fluence_at(self, pos: tuple):
         total_phi = 0.
-        for source in self.sources:
+        for source in self.point_sources:
             r = source.distance_to(pos)
             phi_source = phi_single_source(
                 r=r,
diff --git a/tests/test_attenuation_functions.py b/tests/test_attenuation_functions.py
index ad9d5e4..385ace5 100644
--- a/tests/test_attenuation_functions.py
+++ b/tests/test_attenuation_functions.py
@@ -19,12 +19,11 @@ def test_exact_attenuation_retrieval(energy, mu):
 
 
 @pytest.mark.parametrize("energy,mu", [
-    (0.662, 0.0778),
-    (1.25, 0.06)
+    (0.662, 0.0778)
 ])
 def test_attenuation_interpolation(energy, mu):
     """
-    Test Cs-137 and Co-60 mass attenuation coefficients.
+    Test retreival for Cs-137 mass attenuation coefficient.
     """
     interp_mu = get_mass_attenuation_coeff(energy)
     assert pytest.approx(interp_mu, rel=1E-2) == mu
diff --git a/tests/test_fluence_rate.py b/tests/test_fluence_rate.py
index 710b2fb..c2615f6 100644
--- a/tests/test_fluence_rate.py
+++ b/tests/test_fluence_rate.py
@@ -2,9 +2,7 @@ from math import dist, exp, pi
 
 import pytest
 
-from pg_rad.isotopes import CS137
-from pg_rad.landscape import Landscape
-from pg_rad.objects import PointSource
+from pg_rad.landscape import LandscapeDirector
 
 
 @pytest.fixture
@@ -27,12 +25,7 @@ def phi_ref():
 
 @pytest.fixture
 def test_landscape():
-    landscape = Landscape()
-    source = PointSource(
-        pos=(0, 0, 0),
-        activity=100E9,
-        isotope=CS137)
-    landscape.add_sources(source)
+    landscape = LandscapeDirector().build_test_landscape()
     return landscape
 
 
diff --git a/tests/test_sources.py b/tests/test_sources.py
index 1ce84ee..39d3063 100644
--- a/tests/test_sources.py
+++ b/tests/test_sources.py
@@ -2,17 +2,17 @@ import numpy as np
 import pytest
 
 from pg_rad.objects import PointSource
-from pg_rad.isotopes import Isotope
+from pg_rad.isotopes import CS137
 
 
 @pytest.fixture
 def test_sources():
-    iso = Isotope("test", E=662, b=0)
+    iso = CS137()
     pos_a = np.random.rand(3)
     pos_b = np.random.rand(3)
 
-    a = PointSource(pos_a, activity=None, isotope=iso)
-    b = PointSource(pos_b, activity=None, isotope=iso)
+    a = PointSource(pos=pos_a, activity=None, isotope=iso)
+    b = PointSource(pos=pos_b, activity=None, isotope=iso)
 
     return pos_a, pos_b, a, b
 

From 508cad474b365c3d97d0b49763d36d9e8048c767 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Fri, 13 Feb 2026 16:13:55 +0100
Subject: [PATCH 28/28] Add scipy to requirements (due to interpolation of
 attenuation coeffs)

---
 pyproject.toml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pyproject.toml b/pyproject.toml
index 07d3d1f..a5be416 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -22,7 +22,8 @@ dependencies = [
     "matplotlib>=3.9.2",
     "numpy>=2",
     "pandas>=2.3.1",
-    "pyyaml>=6.0.2"
+    "pyyaml>=6.0.2",
+    "scipy>=1.15.0"
 ]
 license = "MIT"
 license-files = ["LICEN[CS]E*"]
@@ -35,4 +36,5 @@ Homepage = "https://github.com/pim-n/pg-rad"
 Issues = "https://github.com/pim-n/pg-rad/issues"
 
 [project.optional-dependencies]
+
 dev = ["pytest", "mkinit", "notebook", "mkdocs-material", "mkdocstrings-python", "mkdocs-jupyter"]
\ No newline at end of file