SSB-47: refactored dft function

CAL/CalibrationProcessing/lib/processing/inspect.py

@@ -28,9 +28,15 @@ __MHZ_IN_HZ = 1.e6
 
 
 @jit()
-def dft2_numba(x:numpy.ndarray, y:numpy.ndarray, l:numpy.ndarray, m:numpy.ndarray, freq_hz, v:numpy.ndarray, fourier_sign):
-
-    arg_factor = (fourier_sign * 2 * numpy.pi * freq_hz / 299792458.0)
+def dft2_numba(x: numpy.ndarray,
+               y: numpy.ndarray,
+               l: numpy.ndarray,
+               m: numpy.ndarray,
+               freq_hz,
+               v: numpy.ndarray,
+               fourier_sign):
+
+    arg_factor = (fourier_sign * 2 * numpy.pi * freq_hz / light_speed)
     result = numpy.zeros((len(x), len(y)), dtype=numpy.complex64)
     x_down = x.astype(numpy.float32)
     y_down = y.astype(numpy.float32)
@@ -60,7 +66,7 @@ def dft2_numba_loop(x, y, l, m, v, arg_factor, result):
         for j in range(x_len):
             for k in range(v.shape[0]):
 
-                result[i, j] += (v[k] * real_factor[i, j, k] + 1.j * imag_factor[i, j, k])
+                result[i, j] += v[k] * (real_factor[i, j, k] + 1.j * imag_factor[i, j, k])
 
 
 def complex_value_to_color(complex_array: numpy.ndarray, abs_max=None, abs_min=None, log=True):
@@ -129,11 +135,14 @@ def _fft_visibilities_lm_plane(l, m, v, sampling):
     return fft_vis
 
 
-def _dft_visibilities_lm_plane(l, m, v, sampling, frequency):
-    x = numpy.linspace(-30, 30, sampling)
-    y = numpy.linspace(-30, 30, sampling)
+def _dft_visibilities_lm_plane(l, m, v, sampling, frequency, array_size):
 
-    fft_vis = dft2_numba(x, y, l, m, frequency, v, 1)
+    x = numpy.linspace(-array_size, array_size, sampling)
+    y = numpy.linspace(-array_size, array_size, sampling)
+    l = numpy.array(l)
+    m = numpy.array(m)
+    v = numpy.array(v)
+    fft_vis = dft2_numba(x, y, l, m, frequency, v, -1)
 
     return fft_vis
 
@@ -164,22 +173,24 @@ def _plot_station_averaged_visibilities_station_plane_single_frequency(figure: F
     for index, polarization in enumerate(('XX', 'XY', 'YX', 'YY')):
         v_pol = numpy.array(list(map(lambda x: x[polarization], v)))
 
-        fft_vis = _dft_visibilities_lm_plane(l, m, v_pol, sampling, frequency)
+        array_size = 30
+        fft_vis = _dft_visibilities_lm_plane(l=l, m=m, v=v_pol,
+                                             sampling=sampling,
+                                             frequency=frequency,
+                                             array_size=array_size)
 
         canvas = figure.add_subplot(2, 2, index + 1)
-        canvas.set_xlim(-30, 30)
-        canvas.set_ylim(-30, 30)
+        canvas.set_xlim(-array_size, array_size)
+        canvas.set_ylim(-array_size, array_size)
 
         canvas.set_xlabel('x [m]')
         canvas.set_ylabel('y [m]')
 
-        antenna_array_length = light_speed / frequency * sampling / 2. / 2.
-
         color_mapped_fft = complex_value_to_color(fft_vis, log=False)
-        canvas.imshow(color_mapped_fft[:, ::-1], origin='lower', extent=[-1 * antenna_array_length,
-                                                                          1 * antenna_array_length,
-                                                                         -1 * antenna_array_length,
-                                                                          1 * antenna_array_length],
+        canvas.imshow(color_mapped_fft[:, ::-1], origin='lower', extent=[-1 * array_size,
+                                                                          1 * array_size,
+                                                                         -1 * array_size,
+                                                                          1 * array_size],
                       resample = True)
         canvas.set_title(polarization)