a question about numpy

[Robert Kern]

On 2009-09-08 20:45 PM, hi_roger wrote:
> hello, i want to ask a question about numpy.
>
> i know how to select a submatrix using the slice object in numpy. But
> how can i select a submatrix
> A[i1,i2,i3;j1,j2,j3] (elements in A on line i1,i2,i3 and column
> j1,j2,j3 ,  and i1,i2,i3,j1,j2,j3 are all arbitrary numbers )
> The submatrix must share data memory with original matrix.
>
> Any one help? thank you

Sturla is almost correct. What you really want is this:

   i = [[i1], [i2], [i3]]
   j = [[j1, j2, j3]]
   B = A[i, j]

http://docs.scipy.org/doc/numpy/reference/arrays.indexing.html#integer

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-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco