On 6/20/07, Marshall Hampton <[EMAIL PROTECTED]> wrote:
> I now want to do some loops and update certain entries of the matrix.
> But the entries seem immutable, e.g. one can do:
>
> my_matrix[0][0] += 1
>
> and the entry is still zero, although no exception seems to be raised.
>
> So my question is, how can one manipulate individual matrix entries?
To update entries, you should use the [i,j] notation instead of [i][j]:
{{{
sage: my_matrix = matrix(3,10, [0r for x in range(30)])
sage: my_matrix[0,0]=1
sage: my_matrix
[1 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0]
}}}
I don't know why you can use one notation and not the other but I'm
sure theare are more knowledgeable Matrix people here :)
didier
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to sage-support@googlegroups.com
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/sage-support
URLs: http://sage.math.washington.edu/sage/ and http://sage.scipy.org/sage/
-~----------~----~----~----~------~----~------~--~---
