/* Improved Dimension Indexing */
new; cls;
nn=10;
dim=3;
print/rz dimindex1(nn,dim);



/*
**  dimindex1.txt - Dimension Indexing by re-partitioning the same index numbers
** (C) Copyright 2005 Yosuke Amijima. All Rights Reserved.
**
**  Purpose:    Gets improved index numbers for given dimension in a very easy way.
**
**  Format:     x=dimindex1(nn,dim);
**
**  Input:      nn       scalar,    max number of index  (1,2,3,...,nn)
**
**              dim      scalar,    dimension            (1,...,dim)
**
**
**  Output:     x        matrix ,   (nn^dim) x (dim) of resulting index matrix
**
**  Notice:     It takes lots of memory to run. Light version of GAUSS will not work in most cases.
**              Here, index starts from 1 as in GAUSS.
**
**  This algorithm can be easily implemented in EXCEL, Stata, etc... No more hustle on quasi-random sequences.
*/
proc dimindex1(nn,dim);
   local x,b,n,z,y,j;
/* convert x(base 10) to y(base b) */
   x=seqa(1,1,nn^dim-1); 
   b=nn;
   n=maxc(log(x)/log(b))+1;
   z=reshape(b,n,rows(x));
   y=rev(recserrc(x,z))';
/* adjustments */
   y=y+1;                     /* shift all elements by 1    */
   y=ones(1,dim)|y;           /* insert 1's at the 1st row  */
/* re-indexing each number */
   x=zeros(nn^dim,dim);
   j=1;
   do while j<=dim;
      x[.,j]=rerankindx(y[.,j]);
      j=j+1;
   endo;
   retp(x);
endp;

proc rerankindx(x);
   local k,y,i,j;
   k=1;
   y=zeros(rows(x),cols(x));
   j=minc(x);
   do while j<=maxc(x);
      i=1;
      do while i<=rows(x);
         if x[i]==j;
            y[i]=k;
            k=k+1;
         endif;
         i=i+1;
      endo;
      j=j+1;
   endo;
   retp(y);
endp;