how to calculate average of duplicates across multiple rows and columns

[yoyong555]

Hi everyone. 

My data looks like the one below.

Date         ID     Trial1     Trial2     Trial3

Feb 1        A         74         71

Feb 10      A         71         72

Mar 5        B         76          

Mar 12      C         78          

Mar 23      C         79

Mar 30      C         80         80          80  

I need to be able to produce an output like the one below showing the total number of trials per ID and average.

ID   NTrials      Mean

A        4               72

B        1               76

C        5               79.4

Thank you in advance.

Yoyong

[Astounding · Accepted solution]

A relatively straightforward way:

data temp;
   set have;
   array trial {3};
   do k=1 to 3;
      if trial{k} > . then do;
         value = trial{k};
         output;
      end;
   end;
run;

proc summary data=temp nway;
   var value;
   class id;
   output out=want (drop=_type_ _freq_) n = NTrials mean = Mean;
run;