Fixed int/float bug with fractal dim & simplified fractal dim behaviour

gprMax/cython/fractals_generate.pyx

@@ -27,7 +27,7 @@ cpdef void generate_fractal2D(
     int nx,
     int ny,
     int nthreads,
-    int b,
+    float D,
     np.float64_t[:] weighting,
     np.float64_t[:] v1,
     np.complex128_t[:, ::1] A,
@@ -38,7 +38,7 @@ cpdef void generate_fractal2D(
     Args:
         nx, ny: int for fractal surface size in cells.
         nthreads: int for number of threads to use
-        b: int for constant related to fractal dimension.
+        D: float for fractal dimension.
         weighting: memoryview for access to weighting vector.
         v1: memoryview for access to positional vector at centre of array,
             scaled by weighting.
@@ -59,7 +59,7 @@ cpdef void generate_fractal2D(
 
                 # Calulate norm of v2 - v1
                 rr = ((v2x - v1[0])**2 + (v2y - v1[1])**2)**(1/2)
-                B = rr**b
+                B = rr**D
                 if B == 0:
                     B = 0.9
 
@@ -71,7 +71,7 @@ cpdef void generate_fractal3D(
     int ny,
     int nz,
     int nthreads,
-    int b,
+    float D,
     np.float64_t[:] weighting,
     np.float64_t[:] v1,
     np.complex128_t[:, :, ::1] A,
@@ -82,7 +82,7 @@ cpdef void generate_fractal3D(
     Args:
         nx, ny, nz: int for fractal volume size in cells.
         nthreads: int for number of threads to use
-        b: int for constant related to fractal dimension.
+        D: float for fractal dimension.
         weighting: memoryview for access to weighting vector.
         v1: memoryview for access to positional vector at centre of array,
             scaled by weighting.
@@ -105,7 +105,7 @@ cpdef void generate_fractal3D(
 
                 # Calulate norm of v2 - v1
                 rr = ((v2x - v1[0])**2 + (v2y - v1[1])**2 + (v2z - v1[2])**2)**(1/2)
-                B = rr**b
+                B = rr**D
                 if B == 0:
                     B = 0.9
 

gprMax/fractals.py

@@ -56,9 +56,7 @@ class FractalSurface:
         self.nz = zf - zs
         self.dtype = np.dtype(np.complex128)
         self.seed = seed
-        self.dimension = dimension
-        # Constant related to fractal dimension from: http://dx.doi.org/10.1017/CBO9781139174695
-        self.b = -(2 * self.dimension - 7) / 2
+        self.dimension = dimension # Fractal dimension from: http://dx.doi.org/10.1017/CBO9781139174695
         self.weighting = np.array([1, 1], dtype=np.float64)
         self.fractalrange = (0, 0)
         self.filldepth = 0
@@ -100,7 +98,7 @@ class FractalSurface:
             surfacedims[0],
             surfacedims[1],
             config.get_model_config().ompthreads,
-            self.b,
+            self.dimension,
             self.weighting,
             v1,
             A,
@@ -159,9 +157,7 @@ class FractalVolume:
         self.averaging = False
         self.dtype = np.dtype(np.complex128)
         self.seed = seed
-        self.dimension = dimension
-        # Constant related to fractal dimension from: http://dx.doi.org/10.1017/CBO9781139174695
-        self.b = -(2 * self.dimension - 7) / 2
+        self.dimension = dimension # Fractal dimension from: http://dx.doi.org/10.1017/CBO9781139174695
         self.weighting = np.array([1, 1, 1], dtype=np.float64)
         self.nbins = 0
         self.fractalsurfaces = []
@@ -207,7 +203,7 @@ class FractalVolume:
             self.ny,
             self.nz,
             config.get_model_config().ompthreads,
-            self.b,
+            self.dimension,
             self.weighting,
             v1,
             A,