Question

below is the code to create multiple sets of 0’s and fill it with random numbers, im then taking the first column and calculating the maximum value, the problem is I need to be able to do this for every row (i.e rows 2 through 10)
ive tried putting it into a for loop however it doesnt work with the traditional y=1, mx[:,y], y = y+1

can anyone offer some help? cheers

import pylab

mx = pylab.zeros ((10,6))

for j in range(0,10):
    mx[j] = pylab.randn()

p = mx[:,1]
a = max (p)

Answer 1

If you are looking for the max of rows 2 through 10,
then use mx.max(axis=1) to find the max of all rows, and then slice it down to just rows 2 through 10:

mx.max(axis=1)[2:]

For example, if

In [38]: mx = np.arange(60).reshape((10, 6))

In [39]: mx
Out[39]: 
array([[ 0,  1,  2,  3,  4,  5],
       [ 6,  7,  8,  9, 10, 11],
       [12, 13, 14, 15, 16, 17],
       [18, 19, 20, 21, 22, 23],
       [24, 25, 26, 27, 28, 29],
       [30, 31, 32, 33, 34, 35],
       [36, 37, 38, 39, 40, 41],
       [42, 43, 44, 45, 46, 47],
       [48, 49, 50, 51, 52, 53],
       [54, 55, 56, 57, 58, 59]])

Then

In [40]: mx.max(axis=1)[2:]
Out[40]: array([17, 23, 29, 35, 41, 47, 53, 59])

Finally, as larsman has already shown, you can use mx = np.random.randn(10, 6)
to make the random matrix.