First commit. Create class structure, calculation

of voxelization step and preparing of pressure fields.

Co-Authored-By: fuerbringer <severin@fuerbringer.info>
Co-Authored-By: di2pf <vbknrzum@protonmail.com>

Author: 3 people

__init__.py

@@ -0,0 +1,82 @@
+import numpy as np
+from scipy.fftpack import idct, dct
+
+class ARDSimulator:
+
+    C = 343  #  Speed of sound [m/s]
+
+    def __init__(self, room_size, max_simulation_frequency, spatial_samples_per_wave_length=4):
+        '''
+        Instantiates an ARD simulation session.
+
+        Parameters
+        ----------
+        room_size : ndarray
+            Size of the room in meters.
+        max_simulation_frequency : float
+            Uppermost frequency of simulation. Can be dialed in lower to enhance performance.
+        spatial_samples_per_wave_length : int
+            Number of spatial samples per wave length. Usually 2 to 4. Lower values decrease 
+            resolution but enhances performance.
+        '''
+        assert(len(room_size) >= 1, "Room dimensions should be bigger than 1D.")
+        assert(len(room_size) <= 3, "Room dimensions should be lower than 3D.")
+
+        self.room_size = room_size
+        self.max_simulation_frequency = max_simulation_frequency
+        self.H = self.calculate_voxelization_step(
+            spatial_samples_per_wave_length)
+        self.pressure_field = None
+
+    def preprocessing(self):
+        '''
+        Preprocessing stage. Refers to Step 1 in the paper.
+
+        Parameters
+        ----------
+
+        Returns
+        -------
+        '''
+        # Step 1 a). Preparing pressure field. Equates to function p(x) on the paper.
+        self.pressure_field = np.zeros(
+            shape=[len(self.room_size), np.max(self.room_size) / self.H])
+
+        # Step 1 b). Rectangular decomposition. Skipped as of now. TODO: Implement rectangular decomposition
+
+        # Step 1 c). Precomputation for the DCTs to be performed. Skipped partitions as of now. TODO: Implement partitions
+
+    def simulation(self):
+        '''
+        Simulation stage. Refers to Step 2 in the paper.
+
+        Parameters
+        ----------
+
+        Returns
+        -------
+        '''
+        pass
+
+    @classmethod
+    def pressure_field_calculation():
+        pass
+
+    def calculate_voxelization_step(self, spatial_samples_per_wave_length):
+        '''
+        Calculate voxelization step for the segmentation of the room (voxelizing the scene).
+        The cell size is fixed by the chosen wave length and the number of spatial samples per 
+        wave length.
+        Calculation: ℎ <= 𝑐 / (2 * 𝑓_max)
+
+        Parameters
+        ----------
+        spatial_samples_per_wave_length : int
+            Number of spatial samples per wave length. Usually 2 to 4.
+
+        Returns
+        -------
+        float
+            ℎ, the voxelization step. In numerics and papers, it's usually referred to ℎ. 
+        '''
+        return self.C / (spatial_samples_per_wave_length * self.max_simulation_frequency)