# [Numpy-discussion] split matrix

Nils Wagner nwagner@iam.uni-stuttgart...
Thu Nov 27 14:49:07 CST 2008

```On Thu, 27 Nov 2008 17:03:51 +0100
Uwe Schmitt <uschmitt@mineway.de> wrote:
> Hi,
>
> is there an effective way to remove a row with a given
>index from
> a matrix ?
>

>>> A = rand(10,5)
>>> A
array([[ 0.15976517,  0.29574162,  0.21537014,
0.69341324,  0.68713389],
[ 0.28992634,  0.89714962,  0.90299203,
0.22203182,  0.57831945],
[ 0.23814492,  0.09436163,  0.67062125,
0.85923647,  0.64548996],
[ 0.83215097,  0.85178335,  0.49873409,
0.59021905,  0.94631569],
[ 0.5494401 ,  0.08831399,  0.54776161,
0.10043204,  0.88260609],
[ 0.90951225,  0.40967777,  0.78577964,
0.17414472,  0.59568316],
[ 0.97491997,  0.76869065,  0.88901626,
0.69693058,  0.73576195],
[ 0.25971704,  0.67759869,  0.42972164,
0.15069627,  0.13269489],
[ 0.50012917,  0.5866074 ,  0.32205757,  0.3347558
,  0.02555147],
[ 0.66448744,  0.14755343,  0.09963282,
0.22277848,  0.35620143]])
>>> ind
array([0, 0, 0, 0, 1, 0, 0, 0, 0, 0])
>>> A = A[ind==0,:][:,:]
>>> A
array([[ 0.15976517,  0.29574162,  0.21537014,
0.69341324,  0.68713389],
[ 0.28992634,  0.89714962,  0.90299203,
0.22203182,  0.57831945],
[ 0.23814492,  0.09436163,  0.67062125,
0.85923647,  0.64548996],
[ 0.83215097,  0.85178335,  0.49873409,
0.59021905,  0.94631569],
[ 0.90951225,  0.40967777,  0.78577964,
0.17414472,  0.59568316],
[ 0.97491997,  0.76869065,  0.88901626,
0.69693058,  0.73576195],
[ 0.25971704,  0.67759869,  0.42972164,
0.15069627,  0.13269489],
[ 0.50012917,  0.5866074 ,  0.32205757,  0.3347558
,  0.02555147],
[ 0.66448744,  0.14755343,  0.09963282,
0.22277848,  0.35620143]])

Nils

```