do loop or macro for ttest

[xinyao]

I have data  like below:

2 group

30 measure

 site      measure  group   c1 

1            1                1        67   

 1           1                1        74   

1              2                 1       44  

1            2                 1     32  

1           3                 1      124   

1            3                1     137  

1            4                 1      58  

1             4                1   55  

…………….

22290      27              2     18    

22290     27                 2     79                

after summary : 

proc means data=data1 noprint nway;
class group measure;
var c1;
output out=Ave_rates mean=mean; run;

measure  group    mean

1               1             63

1                 2             70

2                1               67

2                  2            68

3                   1              75

3                  2             86

……..

30               1            33

30                2            50

I want to use proc ttest to tests of significance between two group  for each measure, 

I think I may need write a do loop or macro for ttest, or I need use ttest 30 times. someone help me!

Thank you!

[PaigeMiller]

You should be able to use PROC TTEST with a BY MEASURE; statement (which then requires you to sort the data by the MEASURE variable first). You don't need PROC MEANS, you don't need macros, you don't need DO loops.

It is very confusing that you have 30 groups after PROC MEANS but 27 groups before PROC MEANS. Can you explain that?

[ballardw · Accepted solution]

I am guessing that you are looking for something like this:

proc sort data=data1;
   by measure;
run;

proc ttest data=data1;
   by measure;
   class group;
   var c1;
run;

BY group processing, using each value of a variable to perform similar operations, is a core concept in SAS programming.

[xinyao]

Thank you so much!
It works!