A new to Python question

[David]

Hi I'm trying to teach myself python and so far to good, but I'm having
a bit of trouble getting a function to work the way I think it should
work.  Right now I'm taking a simple program I wrote in Fortran and
trying to do it in Python.  I got it to work, but now I'm trying to
modularize it.  My fortran program uses a subroutine and I was trying
to do the same thing in Python.  But I'm still new so I'm having
trouble understanding what I'm doing wrong.  Here is my code:

#! /usr/bin/python
#This program takes two vectors and multiplies them
#against a 10X10 array.  It also then gives the dot product,
#sum, and max value of the array.

import Numeric
def abc(array1,array2,dotprod,sum,maxvalue):
    """Takes two arrays and performs predetermined calculations,
       Then returns the solutions back as the same array, along
       with the dot product, sum, and max value of the array."""
    #TODO: Get this damn thing working!!
    print "Array 1 in:",array1 #Debug
    data = Numeric.zeros((10,10))
    for i in range(10):
        for j in range(10):
            data[i,j] = (i+1)+(j+1)

    e = Numeric.matrixmultiply(data, array1)
    g = Numeric.matrixmultiply(Numeric.transpose(data),array2)
    array1 = e
    array2 = g
    dotprod = Numeric.dot(array1,array2)
    sum = Numeric.sum(array1)
    maxvalue = array2[Numeric.argmax(array2)]
    print "Array 1 out:",array1 #Debug

    return array1,array2,dotprod,sum,maxvalue #<<-- Not working as I
thought it would.

x = Numeric.arange(1,11)
y = Numeric.arange(1,11)*2
dotp,sumx,maxv = 0,0,0  #Is this the only way to declare a variable?

print 'Array X:',x
print 'Array Y:',y
abc(x,y,dotp,sumx,maxv)
print 'Calling function abc'
print 'Array X:',x
print 'Array Y:',y
print 'Dot Product of X and Y:',dotp
print 'Sum of array X:',sumx
print 'Max value of array Y:',maxv

If you run it the data gets passed to the function just fine and it
finds the right numbers.  Its just getting it to pass them back thats
not working.  I put some print statements inside the function just to
see how the data gets passed.  So any ideas that would help me? If you
want to see the fortran code just email me.

David