function B = xrepmat(A,varargin)%XREPMAT Replicate and tile an array.%%   XREPMAT(A,M,N) and XREPMAT(A,[M N]) replicates and tiles the matrix%   A to produce a M-by-N block matrix.%%   XREPMAT(A,(M,N,P,...) and XREPMAT(A,[M N P ...]) tiles the array A%   to produce a M-by-N-by-P-by-... block array.  A can be N-D.%%   XREPMAT(A,M,N) when A is a scalar is commonly used to produce an%   M-by-N matrix filled with A's value.  This can be much faster than%   A*ONES(M,N) when M and/or N are large.%%   Example:%       xrepmat(magic(2),2,3)%       xrepmat(NaN,2,3)%%   See also REPMAT, MESHGRID, NDGRID.%   Author:      Peter J. Acklam%   Time-stamp:  1999-08-24 00:55:23%   E-mail:      jacklam@math.uio.no%   URL:         http://www.math.uio.no/~jacklamif nargin < 2   error( 'Not enough input arguments.' );elseif nargin == 2   if length(varargin{1}) == 1          % XREPMAT(A,M)      Rsiz = [ varargin{1} varargin{1} ];   else                                 % XREPMAT(A,[M N P ...])      Rsiz = varargin{1};   endelse                                    % XREPMAT(A,[M N P ...])   Rsiz = [ varargin{:} ];endif length(A) == 1   nelems = prod(Rsiz);   if nelems > 0      % Since B doesn't exist, the first statement creates a B with the      % right size and type.  Then use scalar expansion to fill the      % array.  Finally reshape to the specified size.      B(nelems) = A;      B(:) = A;      B = reshape(B,Rsiz);   else      B = A(ones(Rsiz));   endelse   Asiz = size(A);   Adim = length(Asiz);   Rdim = length(Rsiz);   if ( Adim == 2 ) & ( Rdim == 2 )      mind = (1:Asiz(1))';      nind = (1:Asiz(2))';      mind = mind(:,ones(1,Rsiz(1)));      nind = nind(:,ones(1,Rsiz(2)));      B = A(mind,nind);   else      Bdim = max(Adim,Rdim);      Asiz = [ Asiz ones(1,Bdim-Adim) ];      Rsiz = [ Rsiz ones(1,Bdim-Rdim) ];      % This might be `clever', but this is usually slower than the      % for-loop below.%      v = reshape( reshape( 1:2*Bdim, Bdim, 2 )', 1, 2*Bdim );%      A = A(:);%      B = reshape( A(:,ones(1,prod(Rsiz))), [ Asiz Rsiz ] );%      B = reshape( permute( B, v ), Asiz.*Rsiz );      for i = 1:Bdim         ind = (1:Asiz(i))';         subs{i} = ind(:,ones(1,Rsiz(i)));      end      B = A(subs{:});   endend