Module « scipy.signal »

Fonction order_filter - module scipy.signal

Signature de la fonction order_filter

def order_filter(a, domain, rank) 

Description

order_filter.__doc__

    Perform an order filter on an N-D array.

    Perform an order filter on the array in. The domain argument acts as a
    mask centered over each pixel. The non-zero elements of domain are
    used to select elements surrounding each input pixel which are placed
    in a list. The list is sorted, and the output for that pixel is the
    element corresponding to rank in the sorted list.

    Parameters
    ----------
    a : ndarray
        The N-dimensional input array.
    domain : array_like
        A mask array with the same number of dimensions as `a`.
        Each dimension should have an odd number of elements.
    rank : int
        A non-negative integer which selects the element from the
        sorted list (0 corresponds to the smallest element, 1 is the
        next smallest element, etc.).

    Returns
    -------
    out : ndarray
        The results of the order filter in an array with the same
        shape as `a`.

    Examples
    --------
    >>> from scipy import signal
    >>> x = np.arange(25).reshape(5, 5)
    >>> domain = np.identity(3)
    >>> x
    array([[ 0,  1,  2,  3,  4],
           [ 5,  6,  7,  8,  9],
           [10, 11, 12, 13, 14],
           [15, 16, 17, 18, 19],
           [20, 21, 22, 23, 24]])
    >>> signal.order_filter(x, domain, 0)
    array([[  0.,   0.,   0.,   0.,   0.],
           [  0.,   0.,   1.,   2.,   0.],
           [  0.,   5.,   6.,   7.,   0.],
           [  0.,  10.,  11.,  12.,   0.],
           [  0.,   0.,   0.,   0.,   0.]])
    >>> signal.order_filter(x, domain, 2)
    array([[  6.,   7.,   8.,   9.,   4.],
           [ 11.,  12.,  13.,  14.,   9.],
           [ 16.,  17.,  18.,  19.,  14.],
           [ 21.,  22.,  23.,  24.,  19.],
           [ 20.,  21.,  22.,  23.,  24.]])