added disc_and_rings to components and made it stim-pkg compatible

stimuli/components/components.py

@@ -237,50 +237,93 @@ def checkerboard(
     return img
 
 
-def disc(
+def disc_and_rings(
         ppd=20,
-        radius=3,
+        radii=(3, 6, 9),
         vback=0.,
-        vdisc=1.,
+        vdiscs=(1., 0., 1.),
         ssf=5,
         ):
     """
-    Create a central disc
+    Create a central disc with rings
 
     Parameters
     ----------
     ppd : int
         pixels per degree (visual angle)
-    radius : float
-        radius of disc in degree visual angle
+    radii : tuple of floats
+        radii of disc in degree visual angle
     vback : float
         value of background
-    vdisc : float
-        value of disc
+    vdiscs : tuple of floats
+        values of discs
     ssf : int (optional)
           the supersampling-factor used for anti-aliasing. Default is 5.
 
     Returns
     -------
     A 2d-array with a disc
     """
-    radius_px = degrees_to_pixels(radius, ppd) * ssf
+    radii_px = degrees_to_pixels(radii, ppd) * ssf
 
     # create stimulus at 5 times size to allow for supersampling antialiasing
-    img = np.ones([radius_px*2, radius_px*2]) * vback
+    img = np.ones([radii_px.max()*2, radii_px.max()*2]) * vback
 
     # compute distance from center of array for every point, cap at 1.0
     x = np.linspace(-img.shape[1] / 2.0, img.shape[1] / 2.0, img.shape[1])
     y = np.linspace(-img.shape[0] / 2.0, img.shape[0] / 2.0, img.shape[0])
     dist = np.sqrt(x[np.newaxis, :] ** 2 + y[:, np.newaxis] ** 2)
-    img[dist < radius_px] = vdisc
+
+    radii_px = radii_px[::-1]
+    vdiscs = vdiscs[::-1]
+    for radius, value in zip(radii_px, vdiscs):
+        img[dist < radius] = value
 
     # downsample the stimulus by local averaging along rows and columns
     sampler = resize_array(np.eye(img.shape[0] // ssf), (1, ssf))
     img = np.dot(sampler, np.dot(img, sampler.T)) / ssf**2
     return img
 
 
+def disc(
+        ppd=20,
+        radius=3,
+        vback=0.,
+        vdisc=1.,
+        ssf=5,
+        ):
+    """
+    Create a central disc
+
+    Parameters
+    ----------
+    ppd : int
+        pixels per degree (visual angle)
+    radius : float
+        radius of disc in degree visual angle
+    vback : float
+        value of background
+    vdisc : float
+        value of disc
+    ssf : int (optional)
+          the supersampling-factor used for anti-aliasing. Default is 5.
+
+    Returns
+    -------
+    A 2d-array with a disc
+    """
+    radius = [radius]
+    vdisc = [vdisc]
+
+    if len(radius) > 1:
+        raise ValueError("Too many radii passed")
+    if len(vdisc) > 1:
+        raise ValueError("Too many values for discs passed")
+
+    img = disc_and_rings(ppd, radius, vback, vdisc, ssf)
+    return img
+
+
 def square_wave_grating(
         ppd=10,
         n_bars=8,