September Morn Update

Task/Mandelbrot-set/Python/mandelbrot-set-4.py

@@ -0,0 +1,26 @@
+import matplotlib.pyplot as plt
+import numpy as np
+
+npts = 300
+max_iter = 100
+
+X = np.linspace(-2, 1, 2 * npts)
+Y = np.linspace(-1, 1, npts)
+
+#broadcast X to a square array
+C = X[:, None] + 1J * Y
+#initial value is always zero
+Z = np.zeros_like(C)
+
+exit_times = max_iter * np.ones(C.shape, np.int32)
+mask = exit_times > 0
+
+for k in range(max_iter):
+    Z[mask] = Z[mask] * Z[mask] + C[mask]
+    mask, old_mask = abs(Z) < 2, mask
+    #use XOR to detect the area which has changed
+    exit_times[mask ^ old_mask] = k
+
+plt.imshow(exit_times.T,
+           cmap=plt.cm.prism,
+           extent=(X.min(), X.max(), Y.min(), Y.max()))