Yes, you can.
I'll present a general technique for writing a module that "wraps" a Base SAS function so that it becomes "vectorized." (This technique is adapted from code that will appear in my forthcoming book Statistical Programming with SAS/IML Software: An Introduction, SAS Press, 2010.)
The issue, for those not familiar with calling Base SAS functions, is that some Base SAS functions string out their arguments in a list, whereas in SAS/IML it is convenient to be able to pass a vector of values. For the case of the IRR function, you can call IRR from IML explicitly by forming a list:
proc iml;
/* call Base SAS function directly to find the answer */
rate1 = IRR(1,-400,100,200,300);
print rate1;
However, in SAS/IML the parameters are typically in a vector such as
c = {-400,100,200,300};
and you cannot call IRR as
rate2 = IRR(1,c); /* WRONG! Can't send vector to function expecting a list */
How can we call the Base SAS function? The key is to define a module that uses the PUTN function to convert the numeric parameters to a long, comma, separated list, then call the EXECUTE subroutine.
/* Call the IRR function in Base SAS.
This technique works for any Base SAS function that
is expecting a list of arguments instead of a vector.
Rick Wicklin */
start myIRR(freq, c);
/* convert numeric matrices a single string */
args = strip(putn(freq,"BEST12.")); /* string of the freq value */
cc = strip(putn(c, "BEST12.")); /* character vector of c */
do i = 1 to nrow(cc)*ncol(cc); /* concatenate all values */
args = concat(args, ",", strip(cc));
end;
cmd = "rate = IRR(" + args + ");" ; /* Base function call, as a string */
call execute(cmd); /* execute the string */
return (rate); /* return result from Base SAS function */
finish;
freq = 1;
c = {-400,100,200,300};
rate = myIRR(freq,c); /* call Base SAS function with vector */
print rate;
