topic Re: Find the maximum of an arrayed variable in SAS Procedures

Find the maximum of an arrayed variable

moreka — Sun, 28 Apr 2013 22:24:44 GMT

I am trying to find the maximum of several variables (ml1-ml9), which are broken up into a before and after group, defined by the value in variable 'before'.

If before=3 then find the maximum of ml1-ml3 and then of ml4-ml9.

If before=6 then find the maximum of ml1-ml6 and then of ml6-ml9.

I tried to do this inside of an array, but unless I'm writing the do loop or array incorrectly, the max function doesn't appear to work in this context:

data amt; set dom; bef=0;

array ml(9) ml1-ml9;

do j=1 to before;

bef+ml(j);

maxbef=max(of ml(j));

---

ERROR 71-185: The MAX function call does not have enough arguments.

What better ways might there be to do this? My other thought was subsetting the data into Before and After datasets with an array by deleting irrelevant data.

Re: Find the maximum of an arrayed variable

Tom — Sun, 28 Apr 2013 22:51:35 GMT

I think you are just going to have to get loopy to meet your requirements.

data amt;

set dom;

array ml(9) ml1-ml9;

do j=1 to before;

MAXBEF = MAX(0,MAXBEF,ml(j));

end;

do j=before+1 to dim(ml);

MAXAFTER = MAX(0,MAXAFTER,ml(j));

end;

run;

Re: Find the maximum of an arrayed variable

moreka — Sun, 28 Apr 2013 23:24:01 GMT

Brilliant, thanks!

Re: Find the maximum of an arrayed variable

Ksharp — Mon, 29 Apr 2013 02:07:39 GMT

Why not use two simple statements ?

MAXBEF = MAX(of ml1-ml4);

MAXAFTER = MAX(of ml4-ml9);

Re: Find the maximum of an arrayed variable

Haikuo — Mon, 29 Apr 2013 02:30:09 GMT

I think 'Before' is a variable whose values may change across obs. Tom's approach is more robust, no more "if ... then" needed.

Haikuo

Re: Find the maximum of an arrayed variable

Ksharp — Mon, 29 Apr 2013 03:17:11 GMT

Agree. I need take a look closer .