Can any body help me with this do loop? - sas

Question

Any one can help me to see what wrong in this do loop? I want to generate outm with 2,3,4 and 5. I need to create a do loop to handle it but I failed.
data Dmatrix5;
input x1 x2 x3 x4 x5;
cards;
0 . . . .
2 0 . . .
15 0 . .
4 3 5 0 .
5 8 7 6 0
;
run;%macro loop
%Do outm=5%to2;
%let inm=5;
%let outm=%eval(&inm-1);
data Dmatrix&outm;
retain minv small large;
array cor{&inm,&inm} _temporary_;
do i=1 to &inm;
set Dmatrix&inm;
array a[&inm] x1--x&inm;
array op[&outm];
do j=1 to &inm;
cor[i,j]=a[j];
end;
end;`
do i=1 to &inm;
if i>1 then do;
do j=1 to i-1;
m=cor{i,j};
if i=2 & j=1 then do;
minv=m;
small=i;
large=j;
delrc=j;
end;
else do;
if minv > m then do;
minv=m;
delrc=i;
if i>j then do;
small=j;
large=i;
end;
else do;
small=i;
large=j;
end;
end;
end;
end;
end;
end;
array out{&inm};
do i=1 to &inm;
do j=1 to i;
if large=i and small=j then out[j]=99999;
else if large=j and small=i then out[j]=99999;
else if j=i then out[j]=0;
else do;
if small=i then do;
if small>j and large >j then do;
if cor[small,j]<cor[large,j] then out[j]=cor[small,j];
else out[j]=cor[large,j];
end;
else if small>j and large<j then do;
if cor[small,j]<cor[j,large] then out[j]=cor[small,j];
else out[j]=cor[j,large];
end;
end;
else if small=j then do;
if small<i and large<i then do;
if cor[i,small]<=cor[i,large] then out[j]=cor[i,small];
else out[j]=cor[i,large];
end;
else if small<i and large>i then do;
if cor[i,small]<=cor[large,i] then out[j]=cor[i,small];
else out[j]=cor[large,i];
end;
end;
else if large=j or large =i then
out[j]=99999;
else out[j]=cor[i,j];
end;
end;
n=1;
do k=1 to &inm;
if k^=delrc then do;
op[n]=out[k];
n=n+1;
end;
end;
if delrc^=i then output;
end;
keep op1-op&outm;
run;
data Dmatrix&outm;
set Dmatrix&outm;
x1=op1;
x2=op2;
keep x1-x2;
run;
%end;
%Mend loop;
%loop;

Answer 1

%Do outm=5%to2;
will never iterate. You need to use %BY -1 to descend by 1. Plenty of documentation.
%macro example1;
%local index;
%do index = 5 %to 2 %by -1;
%put &=index;
%end;
%mend;
%example1
Or you can compute a descending index yourself.
%macro example2;
%local iteration index;
%do iteration = 1 %to 4;
%let index = %eval(6-&iteration);
%put &=index;
%end;
%mend;
%example2