[Scilab-users] circshift() : Scilab Enhancement Proposal

[Samuel Gougeon]

Hello Rafael,

Le 03/01/2018 à 16:00, Rafael Guerra a écrit :
>
> Samuel,
>
> As requested, some further feedback on circshift:
>
>  .../...
>
>   * To add to the wish list: if the input matrix represents a
>     regularly sampled function, it would be useful to have in Scilab a
>     generalization of circshift allowing non-integer shifts, also to
>     have option for non-circular shifts and for padding with zeros
>

To go on about resize_matrix() , padding, and shifting without wrapping:
Specifying a (N>1 x 2) matrix of positive (pad) or negative (trim) 
margins resizing
would be simple.
Padding with other default elements for non-numerical arrays, or with a 
chosen
value, is already enabled.
Possible new syntaxes and examples of usages:

resMat = resize_matrix(mat, frameWidth)
resMat = resize_matrix(mat, frameWidth, ..)
m = [
   6 -7 -1 -2
  -6  0 -2 -5
  -5  4 -1  8
   ];

// shift without extension nor wrapping:
resize_matrix(m, [0 0 ; -1 1])
ans =
   -7 -1 -2  0
    0 -2 -5  0
    4 -1  8  0

// Another case without extensions nor wrapping:
resize_matrix(m, [1 -1 ; 2 -2])
ans =
0  0  0  0
0  0  6 -7
0  0 -6  0

// More general
resize_matrix(m, [2 1 ; 1 -1])
ans =
0  0  0  0
0  0  0  0
0  6 -7 -1
0 -6  0 -2
0 -5  4 -1
0  0  0  0


Is it the kind of features you were thinking about?

IMO, there is no need to implement this in another specific function, 
because these features are just particular cases or resizing, with a 
simple syntax allowing to crop borders as well.

Best regards
Samuel

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.scilab.org/pipermail/users/attachments/20180109/0eb6532c/attachment.htm>