Re: Applying each element of a vector to each row of a matrix

[Jonathan Webster]

Jordi Gutiérrez Hermoso wrote:
> On 19 December 2010 14:59, Jonathan Webster <address@hidden> wrote:
>   
> > Having done a long stint at work using APL, and wanting to save my time
> > rather than the computer's time, I long ago wrote rho.m , implementing
> > the arbitrary  reshape properties of the APL operator of that name.  I
> > can supply it if anyone is interested.
> >     
>
> Yes please. More code for the sharin' (and I promise I'll get around
> some day to finishing that website that should make this kind of
> sharing easier).
>
> - Jordi G. H.
>
>   
Here are further examples:
octave:3> vex = 1:3
vex =

 1  2  3

octave:4> mm = rho ( 2,3,3)
mm =

  2   2   2
  2   2   2
  2   2   2

octave:5> mmm = mm .^ rho(vex,3,3)
mmm =

  2   4   8
  2   4   8
  2   4   8

octave:6> (rho ( 2,3,3) .^ rho((1:3),3,3))
ans =

  2   4   8
  2   4   8
  2   4   8

Be well,
Jonathan

function [arout,ver] =  rho( arin,ny,nx)
%  function arout =  rho( arin,ny,nx)
%  inslpired in name and function by the APL operator of the same name
%  does NOT use Fortran indexing: fills rows first

%author: JCWebster
%cdate: 4/27/2000
%purpose: utility routine like the APL operator 'rho' 
%modified: 6/15/2000 to add revision number
ver = ["RHO","1.2"];

[nyi,nxi]= size(arin);
if (nyi >= 1) 
        arin = reshape (arin,1,(nyi*nxi));
endif

nnTot = ny * nx ; % total number of elemenents in output
arout = zeros(1,nnTot);
lengIn = length( arin); % length of input
ii = 0; % counter in input arg
for iii = 1:nnTot
ii++;
arout(1,iii) = arin(1,ii);
if(ii>=lengIn)
ii=0;
end
end

arout = reshape(arout, nx,ny)';