Brock Lee
12/10/2006 11:51:00 PM
Based on the documentation at ruby-doc.org, I would think that the
following would work for versions 1.8.5 and later. But my version of
Ruby, 1.8.4, does not seem to support it. Here it is:
a[i, j] = field
One potential solution would be to put your data into an Array
initially, and then convert it to a Matrix at the end. Assuming a is
an Array, the following would work:
m = Matrix.rows(a)
By the way, a bit further down you have a conditional:
if i = 5
which should be:
if i == 5
Brock Lee
Jay wrote:
> Hi Folks,
> This is probably quite easy, but I can't find a Matrix function or way
> to populate a specific element of a matrix with a given value? ie, I
> want to tell that element i,j of matrix.a should be 3
> My code below is a simple test to populate a 5 by 5 matrix from values
> in a CSV text file. The loops etc are messy, but it's just an example.
>
>
> require "mathn"
> i=1
> j=1
> a = Matrix.zero(5)
> File.open("TestData.txt").each do |record|
> record.split(",").each do |field|
> field.chomp!
> if i<5 then
> Matrix.a(i,j)=field # <-------------How do I
> do this line?
> end
> if i = 5 then
> i = 1
> j=j+1
> end
> i=i+1
> end
> end
> puts a.to_s
>
> Any Help/pointers would be great.
> TIA.
> Jay.