Function downsample

vispy/testing/image_tester.py:291–314

Downsample by averaging points together across axis. If multiple axes are specified, runs once per axis.

(data, n, axis=0)

def downsample(data, n, axis=0):
    """Downsample by averaging points together across axis.
    If multiple axes are specified, runs once per axis.
    """
    if hasattr(axis, '__len__'):
        if not hasattr(n, '__len__'):
            n = [n]*len(axis)
        for i in range(len(axis)):
            data = downsample(data, n[i], axis[i])
        return data

    if n <= 1:
        return data
    nPts = int(data.shape[axis] / n)
    s = list(data.shape)
    s[axis] = nPts
    s.insert(axis+1, n)
    sl = [slice(None)] * data.ndim
    sl[axis] = slice(0, nPts*n)
    d1 = data[tuple(sl)]
    d1.shape = tuple(s)
    d2 = d1.mean(axis+1)

    return d2


class ImageTester(scene.SceneCanvas):