Hi, no array but another way  ...   data a; input a b @@; datalines; 1 3 0 6 0 7 1 9 1 4 0 2 ;   * place sum of values of variable B in macro variable &TOT; proc sql noprint; select sum(b) into :tot from a; quit;   data want (keep=a b c); set a; cumb + lag(b); c = a*(&tot-cumb) + ^a*b; run;   data set WANT ... Obs    a    b     c  1     1    3    31  2     0    6     6  3     0    7     7  4     1    9    15  5     1    4     6  6     0    2     2 ... View more

Post your log/code then. ... View more

Not as well known, but equally effective here, is a cousin of the LAG function.  These two statements produce identical results: B=a-lag(a); B=dif(a); ... View more

What is the desired output? ... View more

Thanks a lot. ... View more

Thanks Rick: Data sim; Input A B C Beta P; cards; 1 2  3  0.5  0 2 3  4  0.5  1 3 4.5 3  0.5 1 3 5 6  0.5   0 ; Run; proc iml; use sim; read all var _NUM_ into DM; close; A = DM[,1]; B = DM[,2]; C = DM[,3];  Beta = DM[,4];  P = DM[,5]; n = nrow(DM); start Func(x) global( Beta_i, C_i , A_i, P_i); if P_i=0 then do;    return(  exp(-x)*exp(2-x +Beta_i*C_i)#(cdf("Normal", x-2+Beta_i*C_i + A_i)-cdf("Normal", x-1+C_i + A_i)) ); end; else do; return(  exp(-x)*exp(4-x +Beta_i*C_i)#(cdf("Normal", x-4 +Beta_i*C_i + A_i)-cdf("Normal", x-1+C_i + A_i)) ); end; finish; answer = j(nrow(DM),1); do i = 1 to nrow(DM);    Beta_i = Beta; C_i = C; A_i=A; P_i=P; /* set global variables */    call quad(result, "Func", A || B,);    answer = result; end; create kaplan1n var{A  B C Beta P Answer }; append; quit; ... View more

Thanks a lot Rick, I will read the blog as well ... View more

Thanks Tom. ... View more

Data sim; Input A B; cards; 1 3 2 7 3 10 4 12 ; Run; proc iml; use sim; read all  var{A B} into DM; close; A = DM[,1]; B = DM[,2]; n = nrow(DM); start Func(x);    return(  exp(2-x)#cdf("Normal", x) ); finish; answer = j(nrow(DM),1); do i = 1 to nrow(DM); call quad(result, "Func", A || B,); answer = result; end; create kaplan1n var{A  B Answer }; append; quit; ... View more