# [Numpy-discussion] Fill a particular value in the place of number satisfying certain condition by another number in an array.

Brett Olsen brett.olsen@gmail....
Mon Aug 1 09:34:16 CDT 2011

```This method is probably simpler:

In [1]: import numpy as N

In [2]: A = N.random.random_integers(-10, 10, 25).reshape((5, 5))

In [3]: A
Out[3]:
array([[ -5,   9,   1,   9,  -2],
[ -8,   0,   9,   7, -10],
[  2,  -3,  -1,   5,  -7],
[  0,  -2,  -2,   9,   1],
[ -7,  -9,  -4,  -1,   6]])

In [4]: A[A < 0] = 0

In [5]: A
Out[5]:
array([[0, 9, 1, 9, 0],
[0, 0, 9, 7, 0],
[2, 0, 0, 5, 0],
[0, 0, 0, 9, 1],
[0, 0, 0, 0, 6]])

~Brett

On Mon, Aug 1, 2011 at 4:31 AM, dileep kunjaai <dileepkunjaai@gmail.com> wrote:
> Dear sir,
>    How can we fill a particular value in the place of number satisfying
> certain condition by another number in an array.
>
>
> Example:
>  A=[[[  9.42233087e-42  - 4.71116544e-42   0.00000000e+00 ...,
> 1.48303127e+01
>      1.31524124e+01   1.14745111e+01]
>   [  3.91788793e+00   1.95894396e+00   0.00000000e+00 ...,   1.78252487e+01
>      1.28667984e+01   7.90834856e+00]
>   [  7.83592510e+00   -3.91796255e+00   0.00000000e+00 ...,   2.08202991e+01
>      1.25811749e+01   4.34205008e+00]
>   ...,
>   [  -8.51249974e-03   7.00901222e+00   -1.40095119e+01 ...,
> 0.00000000e+00
>      0.00000000e+00   0.00000000e+00]
>   [  4.26390441e-03   3.51080871e+00   -7.01735353e+00 ...,   0.00000000e+00
>      0.00000000e+00   0.00000000e+00]
>   [  0.00000000e+00   0.00000000e+00   0.00000000e+00 ...,   0.00000000e+00
>      0.00000000e+00   0.00000000e+00]]
>
>  [[  9.42233087e-42   -4.71116544e-42   0.00000000e+00 ...,   8.48242474e+00
>      7.97146845e+00   7.46051216e+00]
>   [  5.16325808e+00   2.58162904e+00   0.00000000e+00 ...,   8.47719383e+00
>      8.28024673e+00   8.08330059e+00]
>   [  1.03267126e+01   5.16335630e+00   0.00000000e+00 ...,   8.47196198e+00
>      8.58903694e+00   8.70611191e+00]
>   ...,
>   [  0.00000000e+00   2.74500012e-01   5.49000025e-01 ...,   0.00000000e+00
>      0.00000000e+00   0.00000000e+00]
>   [  0.00000000e+00   1.37496844e-01   -2.74993688e-01 ...,   0.00000000e+00
>      0.00000000e+00   0.00000000e+00]
>   [  0.00000000e+00   0.00000000e+00   0.00000000e+00 ...,   0.00000000e+00
>      0.00000000e+00   0.00000000e+00]]
>
>  [[  9.42233087e-42   4.71116544e-42   0.00000000e+00 ...,   1.18437748e+01
>      9.72778034e+00   7.61178637e+00]
>   [  2.96431869e-01   1.48215935e-01   0.00000000e+00 ...,   1.64031239e+01
>      1.32768812e+01   1.01506386e+01]
>   [  5.92875004e-01   2.96437502e-01   0.00000000e+00 ...,   2.09626484e+01
>      1.68261185e+01   1.26895866e+01]
>   ...,
>   [  1.78188753e+00   -8.90943766e-01   0.00000000e+00 ...,   0.00000000e+00
>      1.27500005e-03   2.55000009e-03]
>   [  9.34620261e-01   -4.67310131e-01   0.00000000e+00 ...,   0.00000000e+00
>      6.38646539e-04   1.27729308e-03]
>   [  8.43000039e-02   4.21500020e-02   0.00000000e+00 ...,   0.00000000e+00
>      0.00000000e+00   0.00000000e+00]]]
>   A contain some negative value i want to change the negative numbers to
> '0'.
> I used 'masked_where', command but I failed.
>
>
>
>
> --
> DILEEPKUMAR. R
> J R F, IIT DELHI
>
>
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> NumPy-Discussion@scipy.org
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>
>
```