[Numpy-discussion] copy mask from existing masked array?

[Olivier Delalleau]

Should work with:
b = numpy.ma.masked_array(b, mask=a.mask)

-=- Olivier

Le 4 mars 2012 13:01, Chao YUE <chaoyuejoy at gmail.com> a écrit :

> Dear all,
>
> I have a matrix with dimension of (360,720) but with all global data.
> I have another land-sea mask matrix with only 2 unique values in it
> (land=1, sea=-1).
> So I can easily create transform the second array to a masked array.
> the problem is, how can I quickly transform the first one to a masked
> array using the same mask as the land-sea mask array?
>
> I hope my question is clear. If not, here is an example:
>
> In [93]: a=np.arange(10).reshape(2,5)
> In [95]: a=np.ma.masked_equal(a,2
> In [96]: a=np.ma.masked_equal(a,8)
>
> In [97]: a
> Out[97]:
> masked_array(data =
>  [[0 1 -- 3 4]
>  [5 6 7 -- 9]],
>              mask =
>  [[False False  True False False]
>  [False False False  True False]],
>        fill_value = 8)
>
> In [100]: b=np.random.normal(0,2,size=(2,5))
>
> I want to convert b to a masked array using exactly the same mask as a.
>
> thanks to all,
> cheers,
>
> Chao
> --
>
> ***********************************************************************************
> Chao YUE
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>
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