how to sort two dimensional array ??

[Robert Kern]

On 2010-01-19 11:00 AM, Robert Somerville wrote:
> Hi;
> i am having trouble trying to sort the rows of a 2 dimensional array by
> the values in the first column .. does anybody know how or have an
> example of how to do this ??? while leaving the remain columns remain
> relative to the leading column

You will want to ask numpy questions on the numpy mailing list:

   http://www.scipy.org/Mailing_Lists

> from numpy import *
>
> a=array( [ [4, 4, 3], [4, 5, 2], [3, 1, 1] ] )
>
> i would like to generate the output (or get the output ...)
>
> b = [ [3,1,1], [4,4,3], [4,5,2] ]

In [4]: import numpy as np

In [5]: a = np.array( [ [4, 4, 3], [4, 5, 2], [3, 1, 1] ] )

In [6]: i = a[:,0].argsort()

In [7]: b = a[i]

In [8]: b
Out[8]:
array([[3, 1, 1],
        [4, 4, 3],
        [4, 5, 2]])

-- 
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