Hi everyone,
I've been trying to create a function using PROC FCMP which will return a confidence interval (CI) using Wilson method. I would like to use the CI directly in a DATA step or PROC SQL. Here is the function :
proc fcmp outlib = work.funcs.CI;
function CI_Wilson(r,n,output $,fmt,alpha) $;
/* Define some values */
p = r/n;
q = 1 - p;
z = probit(1-alpha/2);
/* CI Wilson */
lower = (2*r+z**2-(z*sqrt(z**2+4*r*q)))/(2*(n+z**2));
upper = (2*r+z**2+(z*sqrt(z**2+4*r*q)))/(2*(n+z**2));
/* CI */
if output = "proportion" then ci = strip(put(r,10.)) || " " || strip(put(p,10.4)) || "(" || strip(put(lower,10.4)) || "-" || strip(put(upper,10.4)) || ")";
else if output = "percent" then ci = strip(put(r,10.)) || " " || strip(put(p*100,10.4)) || "(" || strip(put(lower*100,10.4)) || "-" || strip(put(upper*100,10.4)) || ")";
return(ci);
endsub;
quit;
options cmplib = work.funcs;
data _null_;
ci_proportion = CI_Wilson(81,263,"proportion",10.4,0.05);
ci_percent = CI_Wilson(81,263,"percent",10.4,0.05);
put ci_proportion;
put ci_percent;
run;
It works fine if I write directly
strip(put(p,10.4))
but SAS will give me error if I try
strip(put(p,fmt))
ERROR 22-322: Expecting a format name.
ERROR 202-322: The option or parameter is not recognized and will be ignored.
Furthermore, I already wrote a similar macro using DOSUBL and it worked fine with "fmt" as a macro variable. I just think for a simple calculation like this, it would be faster using PROC FCMP. If someone can suggest a solution, it would be greatly appreciated !!!
Thanks
You need to use the putn function, not put.
You need to use the putn function, not put.
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