1.22.3 modifiers and forces

Author: jewels86

CHANGELOG.md

@@ -5,7 +5,8 @@ Axinite uses a derivative of the **semantic versioning system** to record change
 - Patch increments represent bug fixes, modifications that don't directly affect users, progress towards a milestone/goal, or other small changes.
 
 Although releases are only created for every minor or major increment, patch increments are still uploaded to PyPI.
-# 1.22.1-1.22.2 (1/29/25)
+# 1.22.1-1.22.3 (1/29/25)
+- Created modifier utilities (normal force, magnetic force, modifier_from)
 - Added `energy_of` methods for energy of specific bodies
 - Added `can_see` methods for line of sight checks
 # 1.22 (1/26/35)

axinite/__init__.py

@@ -8,7 +8,7 @@
 from axinite.body import Body
 from axinite.functions import vector_magnitude_jit, unit_vector_jit, gravitational_force_jit, body_dtype, \
     get_inner_bodies, _body, create_outer_bodies, timestep, interpret_distance, interpret_mass, interpret_time, \
-    timesteps, clip_scalar, G, state, time_to, mass_to, distance_to, round_limit, gravitational_forces
+    timesteps, clip_scalar, G, state, time_to, mass_to, distance_to, round_limit, gravitational_forces, locate_body
 import axinite.functions as functions
 from axinite.load import load
 from axinite.backends.euler import euler_backend, euler_nojit_backend

axinite/functions.py

@@ -326,4 +326,11 @@ def gravitational_forces(bodies, body, i, n):
     f = np.zeros(3)
     for j, other in enumerate(bodies):
         if i != j: f += ax.gravitational_force_jit(body["m"], other["m"], body["r"][n] - other["r"][n])
-    return f
+    return f
+
+@njit 
+def locate_body(body, bodies):
+    for i, b in enumerate(bodies):
+        if b["n"] == body["n"]:
+            return i
+    return -1

axinite/utils/__init__.py

@@ -1 +1,4 @@
-from axinite.utils.autopilots import rocket_autopilot
+from axinite.utils.autopilots import rocket_autopilot
+from axinite.utils.normal import normal_force_modifier
+from axinite.utils.magnetic import magnetic_force_modifier
+from axinite.utils.modifier import modifier_from

axinite/utils/magnetic.py

@@ -0,0 +1,30 @@
+import numpy as np
+import axinite as ax
+
+def magnetic_force_modifier(charges, magnetic_field):
+    """
+    Returns a modifier function to calculate the magnetic force between bodies in a magnetic field.
+
+    Args:
+        charges (np.ndarray): An array mapping body indexes to their charges.
+        magnetic_field (np.ndarray): The magnetic field vector.
+
+    Returns:
+        function: A modifier function to calculate the magnetic force.
+    """
+    def modifier(body, f, bodies, t, delta, limit, n):
+        charge = charges[ax.locate_body(body, bodies)]
+
+        for i, other in enumerate(bodies):
+            other_charge = charges[i]
+            if other_charge == 0:
+                continue
+
+            distance_vector = other["r"][n-1] - body["r"][n-1]
+            distance = np.linalg.norm(distance_vector)
+
+            force = charge * other_charge * np.cross(magnetic_field, distance_vector) / distance**2
+            f += force
+        
+        return f
+    return modifier

axinite/utils/modifier.py

@@ -0,0 +1,9 @@
+import axinite as ax
+
+def modifier_from(functions: list[tuple['function', 'function']]) -> 'function':
+    def modifier(body, f, bodies, t, delta, limit, n):
+        for function in functions:
+            if function[0](body, f, bodies, t, delta, limit, n):
+                f = function[1](body, f, bodies, t, delta, limit, n)
+        return f
+    return modifier

axinite/utils/normal.py

@@ -0,0 +1,23 @@
+import numpy as np
+import axinite as ax
+
+def normal_force_modifier():
+    """
+    Returns a modifier function to calculate the normal force between bodies.
+
+    Returns:
+        function: A modifier function to calculate the normal force.
+    """
+    def modifier(body, f, bodies, t, delta, limit, n):
+        for other in bodies:
+            if np.array_equal(body["r"][n-1], other["r"][n-1]):
+                continue
+
+            distance_vector = other["r"][n-1] - body["r"][n-1]
+            distance = np.linalg.norm(distance_vector)
+            normal_vector = distance_vector / distance
+            force_magnitude = body["m"] * other["m"] * ax.G / distance**2
+            f += force_magnitude * normal_vector
+        
+        return f
+    return modifier

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "axinite"
-version = "1.22.2"
+version = "1.22.3"
 dependencies = ["numpy", "numba", "vpython", "plotly"]
 authors = [{ name = "Jewels", email = "jewels@jewels86.me" }]
 maintainers = [{ name = "Jewels", email = "jewels@jewels86.me" }]