function for getting angle at each point

stimuli/components/angular.py

@@ -0,0 +1,36 @@
+import numpy as np
+
+from stimuli.utils import resolution
+
+
+def img_angles(visual_size=None, ppd=None, shape=None):
+    """Matrix of angle (relative to center) for each pixel
+
+    Parameters
+    ----------
+    visual_size : Sequence[Number, Number], Number, or None (default)
+        visual size [height, width] of image, in degrees
+    ppd : Sequence[Number, Number], Number, or None (default)
+        pixels per degree [vertical, horizontal]
+    shape : Sequence[Number, Number], Number, or None (default)
+        shape [height, width] of image, in pixels
+
+    Returns
+    -------
+    numpy.ndarray
+        array of shape, with the angle (in rad) relative to center point, for each pixel
+    """
+
+    # Resolve resolution
+    shape, visual_size, ppd = resolution.resolve(shape, visual_size, ppd)
+
+    # Image coordinates
+    x = np.linspace(-visual_size.width / 2.0, visual_size.width / 2.0, shape.width)
+    y = np.linspace(-visual_size.height / 2.0, visual_size.height / 2.0, shape.height)
+    yy, xx = np.meshgrid(y, x)
+
+    # Rotate image coordinates
+    img_angles = -np.arctan2(xx, yy)
+    img_angles %= 2 * np.pi
+
+    return img_angles