function matrix_difference(file1,file2,i,j,n,A,B,C) {
 i=1
 while (getline<file1 == 1){
   for (j=1;j<=NF;j++) {
     A[i,j]=$j;C[i,j]=A[i,j]-get_i_j(file2,i,j)
   }
   B[i]=NF
   i++
 }
 close(file1)
 n=i-1
 for (i=1;i<=n;i++){
   s=""
   for (j=1;j<=B[i];j++){
     s=s" "C[i,j]
   }
   s=substr(s,2)
   print s > "tmp"
 }
 close("tmp") 
}
function get_i_j(file,i,j,A,i1,j1){
 i1=1
 while (getline<file == 1){
   for (j1=1;j1<=NF;j1++) {
     A[i1,j1]=$j1;
	 if (i==i1 && j==j1) {
	    close(file)
	    return A[i1,j1]
   }
   i1++
 }
 return 0
 close(file)
}