Complex sine example

examples/complex_sine.py

@@ -0,0 +1,59 @@
+# -*- coding: utf-8 -*-
+"""Cisoid at varying frequencies, with and without linear amplitude modulation."""
+import numpy as np
+import matplotlib.pyplot as plt
+from complex_colormap.cplot import const_chroma_colormap, max_chroma_colormap
+
+#%% Helpers ------------------------------------------------------------------
+def gen_x(N, f, AM):
+    t = np.arange(N)/N
+    xbase = np.cos(2*np.pi*f*t) + 1j*np.sin(2*np.pi*f*t)
+    x = np.repeat(xbase[None], N, 0)
+    if AM:
+        x *= t[::-1]
+    return x
+
+def imshow(s, alpha=None, cmap=None, aspect='auto',
+           interpolation='nearest', title=None, **kw):
+    fig = plt.figure()
+    ax = plt.gca()
+    ax.imshow(s, cmap=cmap, alpha=alpha, aspect=aspect,
+              interpolation=interpolation, **kw)
+    _ = [getattr(ax, 'set_%s' % s)([]) for s in
+         ('xticks', 'yticks', 'xticklabels', 'yticklabels')]
+    if title:
+        ax.set_title(title, loc='left', weight='bold', fontsize=24)
+    plt.show()
+
+cms = {'max': max_chroma_colormap,
+       'const': const_chroma_colormap}
+
+#%% Configure (sandbox) ------------------------------------------------------
+# interactive example
+
+# colormap mode
+mode = ('max', 'const')[0]
+# sine length
+N = 512
+# sine frequency
+f = 2
+# whether to use amplitude modulation
+AM = 0
+
+# Execute --------------------------------------------------------------------
+cm = cms[mode]
+x = gen_x(N, f, AM)
+s = cm(x)
+imshow(s)
+
+#%% Run example --------------------------------------------------------------
+N = 512
+for mode in ('const', 'max'):
+    for f in (1, 2):
+        for AM in (0, 1):
+            title = 'cisoid: f={}{} | {}_chroma'.format(
+                f, ', AM' if AM else '', mode)
+            cm = cms[mode]
+            x = gen_x(N, f, AM)
+            s = cm(x)
+            imshow(s, title=title)