topic Re: do loop or macro for ttest in SAS Programming

do loop or macro for ttest

xinyao — Tue, 05 Feb 2019 15:35:17 GMT

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!

Re: do loop or macro for ttest

PaigeMiller — Tue, 05 Feb 2019 15:40:13 GMT

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?

Re: do loop or macro for ttest

ballardw — Tue, 05 Feb 2019 15:52:40 GMT

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.

Re: do loop or macro for ttest

xinyao — Tue, 05 Feb 2019 16:06:23 GMT

Thank you so much!
It works!