How to define a array with variable array-elements?

Hi, all, --I intended to do following caculation. (Attached are the codes, you may skip some part,I put all code here,just for the sake of less chance of misunderstanding)

--The number of record is changing according to different data set, so I intend to a array like: array ma{&num_rec} 8. m1-m&num_rec; This does not work.

Any insight how to do this? TIA. Amy

data test; input m c cc; datalines; 40 0 0 30 0 0 20 0 0 10 0 0 ; run;

%macro get_weight(p_infile=,col1=,col2=,col3=,p_w_rate=w_rate); /*try to get the number of records in the data set*/ data _null_; set &p_infile; retain n 0; n=n+1; call symput('num_rec',n); run;

proc transpose data=&p_infile(keep=&col1) out=out1 PREFIX=m ; proc transpose data=&p_infile(keep=&col2) out=out2 PREFIX=c; proc transpose data=&p_infile(keep=&col3) out=out3 PREFIX=cc;

data finalset; merge out1 out2 out3; run;

data output1; set finalset; /* want to change this m1-m4 to some thing like m1-m&num_rec*/ array ma{&num_rec} 8. m1-m4; array ca{&num_rec} 8. c1-c4; array cca{&num_rec} 8. cc1-cc4; array m_perc{&num_rec} 8.; array c_perc{&num_rec} 8.; array w_perc{&num_rec} 8.;

&p_w_rate=0; m_tot=0; c_tot=0; w_tot=0;

/*do some caculate*/ do i=1 to &num_rec; m_tot=m_tot+ma{i}; c_tot=c_tot+ca{i}; end;

do i=1 to &num_rec; m_perc{i}=ma{i}/m_tot; c_perc{i}=ca{i}/c_tot; end;

do i=1 to &num_rec; w_perc{i}=m_perc{i}/c_perc{i}*cca{i}; w_tot=w_tot+w_perc{i}; end; if w_tot=0 or c_tot=0 then &p_w_rate=0; else &p_w_rate=w_tot/c_tot; keep &p_w_rate; %mend;

%get_weight(p_infile=test,col1=m,col2=c,col3=cc,p_w_rate=w_rate); data _null_; set output1; call symput('w_rate',w_rate); run; %put &w_rate; run;