/*2 宏Macro*/
/*2.1 宏变量*/
%let name1=name;
%let name2=‘name’;
proc print data=xie.class;
where height=67;
title “&name1 ‘s height is 67.”;
title2 “&name2 ‘s height is 67.”;
run;
/*2.2 定义宏*/
/*参数宏*/
%macro try(proc,dsn);
proc &proc data=&dsn;
run;
%mend try;
%try(print,xie.class);
/*无参数宏*/
%macro plot;/*开始定义宏：PLOT*/
proc plot;
plot income*age;
run;
%mend plot; /*结束宏的定义*/
data newdata; /*创建数据集*/
input name $ age income;
cards;
xie 26 3200
wang 23 4400
wu 33 3872
zhou 19 5400
meng 22 5580
;
run;
%plot/*调用宏，绘制收入关于年龄的散点图*/
proc print;run;
data newdata2; /*筛选年龄大于20的记录，建立新数据集*/
set newdata;
if age>20;Run;
%plot/*再次调用宏，绘制收入关于年龄的散点图*/
proc print;
run;
/*2.3 宏函数*/
/*2.4 宏表达式*/
/*2.5 宏语句*/
/*2.6 案例*/
/* The Following macro function can find the first position of "exception" in "source" string */
%macro indexc(source, exception,delimiter=%str( ));
/* the leading and tailling blanks will be delete by way of the following statement */
%let exception =%trim(%left(&exception));
%local count word result temp;
%let count=1;
%let temp=0;
%let result=0;
%let word=%qscan(&exception,&count,&delimiter);
%do %while (&word ne);
%if (%index(&source,&word) ne 0) %then %do;
%let temp=%index(&source,&word);
%if (&temp < &result) or (&result = 0) %then %let result=&temp;%end;
%let count=%eval(&count+1);
%let word=%qscan(&exception,&count,&delimiter);
%end;
&result
%mend indexc;
%indexc(am, I am a teacher,delimiter=%str( ));
%macro a;
%local z;
%let z=%indexc( xie18 - xie6, 1 2 3 4 5 6 7 8 9 0,delimiter=%str( ));
%put &z;
%mend a;
%a;
/*案例二*/
/* comma split */
%macro split(indata,outdata);
data &outdata ;
set &indata;
length str $10;
str=trim(left(etiology));
%do i=1 %to 2;
len=length(str);
if trim(left(str))='' then len=0;
sep_xie=index(str,",");
if sep_xie=0 then do;
if &i=1 then do;
etiology_&i=str+0;
str='';end;
else etiology_&i=.;
end;
if sep_xie=1 then do;
etiology_&i=.;str=left(substr(str,sep_xie+1));
end;
if sep_xie>1 then do;
etiology_&i=left(substr(str,1,sep_xie-1))+0;
str=left(substr(str,sep_xie+1));
end;
%end;
rename str=etiology_code;
drop len sep_xie;
run;
%mend split;
%split(xie.study,study);