feat: Add arctan2 example

Signed-off-by: Sietze van Buuren <[email protected]>

examples/arctan2.py

@@ -0,0 +1,27 @@
+"""
+Surface plot of arctan2 function
+"""
+
+import numpy as np
+import mlpyqtgraph as mpg
+
+
+@mpg.plotter(antialiasing=True)
+def main():
+    """ Examples with surface plots """
+    extent = 4
+    nx = 48
+    ny = 48
+    amplitude = 0.5
+    x = np.linspace(-extent, extent, nx)
+    y = np.linspace(-extent, extent, ny)
+    z = np.zeros((nx, ny))
+    for i in range(ny):
+        z[i, :] = amplitude * np.arctan2(x, y[i])
+
+    mpg.figure(title='arctan2(x, y)', layout_type='Qt')
+    mpg.surf(x, y, z, colormap='viridis', projection='orthographic')
+
+
+if __name__ == '__main__':
+    main()