Re: Tensor product question

[JFCardoso]

I find Jordi's proposal a bit mysterious. 
Here is an alternate version which
looks more transparent, at least to me.
Cheers, JF

###########################################
function out = vector_tensor_product (varargin)
  n = length (varargin);
  dims = zeros(n,1) ;

  out = varargin{1}(:);
  dims(1) = length(out) ;

  for i = 2:n
    dims(i) = length(varargin{i}) 
    out = out(:) * varargin{i}(:)' ;
  endfor

  out = reshape(out, dims) ;
endfunction 
###########################################



On 14 May 2013 16:11, Nir Krakauer <address@hidden> wrote:
> Given d vectors v_1, v_2, v_3, v_4, ..., is there a general way to get
> the d-dimensional tensor product
>
> A(i, j, k, l,...) = v_1(i) * v_2(j) * v_3(k) * v_4(l) * ...

This is kinda ugly, but...

    function out = vector_tensor_product (varargin)

      n = length (varargin);
      p = 1:n;

      out = varargin{1}(:);
      for i = 2:n
        pp = p;
        pp([1,i]) = pp([i,1]);
        out = out .* permute (varargin{i}(:), pp);
      endfor
    endfunction





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