[racket] How to iterate through the arrays in a matrix?

From: Animesh Pandey (animeshpandey.etno at gmail.com)
Date: Fri Nov 28 16:56:13 EST 2014

(map
 (λ(i)
   (matrix-
    (list->matrix 1 4 i)
    (list->matrix 1 4 arr)))
 final-data)

I used this method where final-data is a list of lists and I iterate
through each list, convert it to a matrix and then subtract a pre-defined
constant list to it. What I really need is a way to iterate through a
matrix and not a list of lists as I have do to a lot of matrix operations.


On Fri, Nov 28, 2014 at 4:41 PM, Animesh Pandey <
animeshpandey.etno at gmail.com> wrote:

> Hi,
> I have a 80 X 4 matrix. I have iterate through each row and subtract each
> row with another array at each iteration. At first I thought to convert all
> array to list and do all the operations and then again convert the final
> list if lists to a matrix. But I somehow think that is not a suited way. I
> tried using "for*/matrix" but could not get it right. Could any one give an
> example on how to iterate a matrix (array for arrays)?
>
> My matrix looks like this:
> > (list*->matrix final-data)
> (array
>  #[#[5.1 3.5 1.4 0.2]
>    #[4.9 3.0 1.4 0.2]
>    #[4.7 3.2 1.3 0.2]
>    #[4.6 3.1 1.5 0.2]
>    #[5.0 3.6 1.4 0.2]
>    #[5.4 3.9 1.7 0.4]
>    #[4.6 3.4 1.4 0.3]
>    #[5.0 3.4 1.5 0.2]
>    #[4.4 2.9 1.4 0.2]
>    #[4.9 3.1 1.5 0.1]
> ...........
>
> Thanks!
>
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