[Numpy-discussion] np.where: x and y need to have the same shape as condition ?

denis denis-bz-gg@t-online...
Tue Jan 29 05:16:43 CST 2013


Folks, 
  the doc for `where` says "x and y need to have the same shape as condition"
http://docs.scipy.org/doc/numpy-dev/reference/generated/numpy.where.html
But surely
    "where is equivalent to:
    [xv if c else yv for (c,xv,yv) in zip(condition,x,y)]"
holds as long as len(condition) == len(x) == len(y) ?
And `condition` can be broadcast ?
    n = 3
    all01 = np.array([ t for t in np.ndindex( n * (2,) )]) # 000 001 ...
    x = np.zeros(n)
    y = np.ones(n)
    w = np.where( all01, y, x )  # 2^n x n  

Can anyone please help me understand `where`
/ extend "where is equivalent to ..." ?
Thanks,
cheers
  -- denis



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