R/gridmake.R

In randall-romero/CompEconR: An R version of Miranda & Fackler's CompEcon toolbox for MATLAB

# % GRIDMAKE Forms grid points
# % USAGE
# %   X=gridmake(x);
# %   X=gridmake(x1,x2,x3,...);
# %   [X1,X2,...]=gridmake(x1,x2,x3,...);
# %   X=gridmake({y11,y12},x2,{y21,y22,y23});
# %
# % Expands matrices into the associated grid points.
# % If N is the dx2 matrix that indexes the size of the inputs
# %   GRIDMAKE returns a prod(N(:,1)) by sum(N(:,2)) matrix.
# %   The output can also be returned as either
# %      d matrices or 
# %      sum(N(:,2)) matices
# % If any of the inputs are grids, they are expanded internally
# % Thus
# %    X=gridmake({x1,x2,x3})
# %    X=gridmake(x1,x2,x3)
# % and
# %    x={x1,x2,x3}; X=gridmake(x{:})
# % all produce the same output.
# %
# % Note: the grid is expanded so the first variable change most quickly.
# %
# % Example:
#   %  X=gridmake([1;2;3],[4;5])
# % produces
# %     1     4
# %     2     4
# %     3     4
# %     1     5
# %     2     5
# %     3     5
# % 
# % The function performs an action similar to NDGRID, the main difference is in the
# %   increased flexability in specifying the form of the inputs and outputs.
# %
# % Also the inputs need not be vectors.
# %   X=gridmake([1;2;3],[4 6;5 7])
# % produces
# %     1     4     6
# %     2     4     6
# %     3     4     6
# %     1     5     7
# %     2     5     7
# %     3     5     7
# % 
# % See also: ndgrid
# 
# % Copyright (c) 1997-2000, Paul L. Fackler & Mario J. Miranda
# % paul_fackler@ncsu.edu, miranda.4@osu.edu
# 


gridmake <- function(xlist){
  
  
  stop('try expand.grid instead of gridmake')
  
  
  gridmake2 <- function(X1,X2){
    if (is.null(X1)){return(X2)}
    ix <- expand.grid(1:nrow(X1),1:nrow(X2)) # get row indices
    Z  <- cbind(X1[ix$Var1,],X2[ix$Var2,])   # build grid
    return(Z)
  }
  
  Z  <- NULL
  
  for (i in 1:length(xlist)){
    xi <- if(is.matrix(xlist[[i]])) xlist[[i]] else matrix(xlist[[i]],ncol=1)
    Z <- gridmake2(Z,xi)
  }
  return(Z)
  
  
  
  
  
  
  # n=nargout;
  
}























# function varargout=gridmake(varargin)
# m=prod(size(varargin));
# n=nargout;
# Z=[];
# d=zeros(1,m+1);
# for i=1:m
# if isa(varargin{i},'cell')
# Z=gridmake2(Z,gridmake(varargin{i}{:}));
# else
#   Z=gridmake2(Z,varargin{i});
# end
# d(i+1)=size(Z,2);
# end
# 
# varargout=cell(1,max(n,1));
# if n<=1
# varargout{1}=Z;
# elseif n==m
# for i=1:m
# varargout{i}=Z(:,d(i)+1:d(i+1));
# end
# elseif n==size(Z,2)
# for i=1:n
# varargout{i}=Z(:,i);
# end
# else
#   error(['An improper number of outputs requested - should be 1, ' num2str(m)  ' or ' num2str(size(Z,2))])
# end
# 
# % Expands gridpoints for 2 matrices
# function Z=gridmake2(X1,X2)
# if isempty(X1); Z=X2; return; end
# m=size(X1,1);
# n=size(X2,1);
# ind1=(1:m)';
# ind2=1:n;
# Z=[X1(ind1(:,ones(n,1)),:) X2(ind2(ones(m,1),:),:)];