小编pha*_*ann的帖子

我正在寻找一种将numpy数组分割成重叠块的有效方法.我知道这numpy.lib.stride_tricks.as_strided可能是要走的路,但我似乎无法绕过它在一个广义函数中的用法,该函数适用于任意形状的数组.以下是一些特定应用的例子as_strided.

这就是我想要的:

import numpy as np
from numpy.lib.stride_tricks import as_strided

def segment(arr, axis, new_len, step=1, new_axis=None):
    """ Segment an array along some axis.

    Parameters
    ----------
    arr : array-like
        The input array.

    axis : int
        The axis along which to segment.

    new_len : int
        The length of each segment.

    step : int, default 1
        The offset between the start of each segment.

    new_axis : int, optional
        The position where the newly created axis is to be …

我想重载size()我的一个类的函数,以便它不返回对象的大小,而是返回特定成员的大小.问题是Matlab在类构造函数中调用obj.size以确定对象数组的大小.

例如:

classdef dataClass < handle

properties
    memberVar
end

methods 
    function obj = dataClass(mvIn)
        if nargin ~= 0
            if ~ismatrix(mvIn)
                error('Input must be a matrix');
            end

            obj.memberVar = mvIn;
        end
    end

    function sz = size(obj, varargin)
        h = @(x)builtin('size', x, varargin{:});
        sz = cell2mat(cellfun(h, {obj.memberVar}', 'uni', 0));
    end       
end

end

不起作用,因为对象数组的大小与memberVar的大小相同

a = dataClass(ones(100))

a = 

  100x100 dataClass array with properties:

  memberVar: [100x100 double]

解决方法是将重载实现为

function sz = size(obj, varargin)
    idx = strcmpi(varargin, 'mv');
    if any(idx)
        varargin = …