topic Re: Apply Cochran test on a long dataset in SAS Programming

Apply Cochran test on a long dataset

tSAS1 — Thu, 09 Dec 2021 16:15:11 GMT

I have the dataset below, and I want to know if there is a difference in Response between SoilTest, Irrigati, MowHeigh and Clipping, but I want to use the long format of the data:

data data;
   input Practice $ Student $ Response $;
   datalines;
 SoilTest     a         Yes
 SoilTest     b         No
 SoilTest     c         Yes
 SoilTest     d         Yes
 SoilTest     e         No
 SoilTest     f         Yes
 SoilTest     g         Yes
 SoilTest     h         Yes
 SoilTest     i         No
 SoilTest     j         Yes
 SoilTest     k         Yes
 SoilTest     l         Yes
 SoilTest     m         Yes
 SoilTest     n         Yes
 Irrigation   a         Yes
 Irrigation   b         No
 Irrigation   c         No
 Irrigation   d         No
 Irrigation   e         No
 Irrigation   f         No
 Irrigation   g         No
 Irrigation   h         No
 Irrigation   i         Yes
 Irrigation   j         No
 Irrigation   k         No
 Irrigation   l         No
 Irrigation   m         No
 Irrigation   n         No
 MowHeight    a         Yes
 MowHeight    b         No
 MowHeight    c         Yes
 MowHeight    d         Yes
 MowHeight    e         Yes
 MowHeight    f         Yes
 MowHeight    g         Yes
 MowHeight    h         Yes
 MowHeight    i         No
 MowHeight    j         Yes
 MowHeight    k         Yes
 MowHeight    l         Yes
 MowHeight    m         Yes
 MowHeight    n         Yes
 Clippings    a         Yes
 Clippings    b         No
 Clippings    c         No
 Clippings    d         Yes
 Clippings    e         Yes
 Clippings    f         No
 Clippings    g         No
 Clippings    h         Yes
 Clippings    i         Yes
 Clippings    j         Yes
 Clippings    k         Yes
 Clippings    l         No
 Clippings    m         Yes
 Clippings    n         No
;
run;

Actually this code working, but with changing the shape of the table:

proc sort data=data;by student;run;

proc transpose data=data out=data_test(drop=_NAME_);
ID Practice;
BY student;
VAR Response;
run;

proc freq data=data_test;
   tables SoilTest Irrigati MowHeigh Clipping/nocum;
   tables SoilTest*Irrigati*MowHeigh*Clipping/agree noprint;
run;

is there any possibility to have the same pvalue of Cochran test, without changing the shape of the data, it means :using the long format of data without doing transpose ?

Re: Apply Cochran test on a long dataset

FreelanceReinh — Thu, 09 Dec 2021 16:59:07 GMT

Hello @tSAS1,

I believe that a DATA step can be used to compute the test statistic and p-value, as was demonstrated for a different dataset in Re: Computing multiway tables using indexed variables and proc freq. But I'm not sure why you wouldn't use your existing approach using PROC TRANSPOSE and PROC FREQ, unless your real dataset is much larger so that the DATA step might outperform PROC FREQ.

Re: Apply Cochran test on a long dataset

tSAS1 — Thu, 09 Dec 2021 17:09:32 GMT

Hello thanks @FreelanceReinh

Actually I want to use that code in a macro, so it will not be easy to enter each variable (modalities of Practice variable) in proc freq

Re: Apply Cochran test on a long dataset

data_null__ — Thu, 09 Dec 2021 18:08:37 GMT

You can use programming to generate the table statements.

proc sort;
   by student practice;
   run;
proc transpose data=data out=data_test(drop=_NAME_);
   ID Practice;
   BY student;
   VAR Response;
   run;
proc print;
   run;
proc transpose data=data_test(obs=0 drop=Student) out=practice;
   var _all_;
   run;
proc sql noprint;
   select _name_,_name_ into :agree SEPARATED '*',:oneway SEPARATED ' ' from practice;
   quit;
%put NOTE: &=agree &=oneway;

proc freq data=data_test;
   tables &oneway / nocum;
   tables &agree/agree ;
   run;

@tSAS1 wrote:

Hello thanks @FreelanceReinh

Actually I want to use that code in a macro, so it will not be easy to enter each variable (modalities of Practice variable) in proc freq

Re: Apply Cochran test on a long dataset

tSAS1 — Fri, 10 Dec 2021 08:33:42 GMT

Thank you, this method is working very well!