/* ******************************************************************** */
/* */
/* This macro creates a random sample from a normal distribution of */
/* size = size1 with mean=mean and standard deviation = std. This */
/* generated data is placed in a file name of your choice = filename. */
/* The variable name for the data is your choice = colmnname. This */
/* This macro either prints this data or not, depending upon the print */
/* option of yes or no. Next, this macro takes a sample from the */
/* already generated sample and places it in a data file name of your */
/* choice = sampname. This sample has size = size2. */
/* */
/* The purpose of this macro is to be able to draw a random sample of */
/* size = n from a simulated normal distribution. e.g. the first */
/* distribution might be of size = 1000; so you may want the print */
/* option to be off. */
/* */
/* Example: Suppose I want to generate 3 random samples of size 5 from */
/* a simulated N(100,5^2) distribution. Code is as follows: */
/* */
/* */
/* %random(nordist1,1000,N100_5_1,100,5,samp1,5,no); */
/* */
/* %random(nordist2,1000,N100_5_2,100,5,samp2,5,no); */
/* */
/* %random(nordist3,1000,N100_5_3,100,10,samp3,5,no); */
/* */
/* data merged; */
/* merge samp1 samp2 samp3; */
/* proc print data=merged; */
/* run; */
/* */
/* */
/* */
/* */
/* ******************************************************************** */
%macro random(filename,size1,colmname,mean,std,sampname,size2,print);
data &filename;
retain _seed_ 0;
do _i_ = 1 to &size1;
&colmname = &mean + &std * rannor(_seed_);
output;
end;
drop _seed_ _i_;
run;
%if &print=yes %then %do;
proc print data=&filename;
%end;
/* Below is rearranging the data set 'filename' by using a uniform random */
/* number generator */
/* No real reason to do this */
proc sql;
create view norsam as
select *, RANUNI(0) as _ran_ from &filename
order by calculated _ran_;
quit;
%if &print=YES %then %do;
proc print data=norsam;
%end;
/* Below creates new data set of a different sample size */
data &sampname;
set norsam(obs = &size2);
drop _ran_;
proc print data=&sampname;
%mend random;
/* **************** END OF MACRO ****************** */
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