SAS PROGRAMMING
                                    HANDOUT #21

    This handout writes a SAS macro to check for creating GROUPs of data based on
pre-determined equal spaced cutpoints.


OPTIONS MACROGEN;           *this will generate output helpful in finding errors;

%MACRO GROUP1(DATA1=,DATA0=,VAR=,LOW=,HIGH=,WIDTH=);
%*************************************************************************
Macro parameters:
DATA1  - name of output data set
DATA0  - name of input data set
VAR    - variable to be made into groups
LOW    - left endpoint of lowest interval
HIGH   - right endpoint of highest interval
WIDTH  - width of intervals
%*************************************************************************;
DATA &DATA1; SET &DATA0;
  NN=1;
  GROUP=1;
  %DO N=&LOW %TO &HIGH %BY &WIDTH;      %*the values in the %DO loop should be integers;
   IF &LOW <= &VAR < %EVAL(&LOW+&WIDTH) THEN GROUP=NN;
   NN+1;
   %LET LOW=%EVAL(&LOW+&WIDTH);
  %END;
  DROP NN;
 PROC PRINT;                      ************************************************;
%MEND;                            *a macro can be saved on a diskette, for example;
                                  * as   A:\GROUP.SAS                          ;
                                  *and then invoked with the command:             ;
                                  *    %INCLUDE 'A:\GROUP.SAS';                ;
                                  ************************************************;

DATA JIM;
 INPUT X @@;
CARDS;
100 45 52 45 49 3 12 34 120 4 89 93 36 85 48 92 18 9

%GROUP1(DATA1=OUT,DATA0=JIM,VAR=X,LOW=0,HIGH=150,WIDTH=30);

                               *the values LOW, HIGH, and WIDTH must be integers;

PROC PRINT DATA=OUT;
PROC FREQ DATA=OUT; TABLES GROUP;
RUN;

================================================================================================

    This is very similar to the above program except that it computes the LOW and HIGH
values using the MIN and MAX of the data.


OPTIONS MACROGEN;           *this will generate output helpful in finding errors;

%MACRO GROUP2(DATA1=,DATA0=,VAR=,WIDTH=);
%*************************************************************************
Macro parameters:
DATA1  - name of output data set
DATA0  - name of input data set
VAR    - variable to be made into groups
WIDTH  - width of intervals
%*************************************************************************;
DATA &DATA1; SET &DATA0;
PROC MEANS NOPRINT; VAR &VAR;
 OUTPUT OUT=AA MIN=LL MAX=HH;        %*the values in the %DO loop should be integers;
DATA AA; SET AA;
 LL=INT(LL); HH=INT(HH);
 CALL SYMPUT('LOW',LL);
 CALL SYMPUT('HIGH',HH);
DATA &DATA1; SET &DATA1;
  NN=1;
  GROUP=1;
  %DO N=&LOW %TO &HIGH %BY &WIDTH;
   IF &LOW <= &VAR < %EVAL(&LOW+&WIDTH) THEN GROUP=NN;
   NN+1;
   %LET LOW=%EVAL(&LOW+&WIDTH);
  %END;
  DROP NN;
 PROC PRINT;

%MEND;

DATA JIM;
 INPUT X @@;
CARDS;
100 45 52 45 49 3.2 12 34 120.4 4 89 93 36 85 48 92 18 9

%GROUP2(DATA1=OUT,DATA0=JIM,VAR=X,WIDTH=30);
PROC PRINT DATA=OUT;
PROC FREQ DATA=OUT; TABLES GROUP;
RUN;
======================================================================================================

       This handout writes a SAS macro to check for creating GROUPs of data based on
pre-determined equal spaced cutpoints, without the restriction of integer values.


OPTIONS MACROGEN MPRINT SYMBOLGEN;
TITLE; FOOTNOTE;
%MACRO GROUP3(DATA1=,DATA0=,VAR=,LOW=,HIGH=,WIDTH=);
DATA &DATA1; SET &DATA0;
  NN=1;
  GROUP=1;

  %LET DD=%SYSEVALF((&HIGH-&LOW)/&WIDTH);
  %LET AA=%SCAN(&DD,1,'.');
  %LET BB=%EVAL(&AA+1);

  %DO N=1 %TO  &BB %BY 1;
   IF &LOW <= &VAR < %SYSEVALF(&LOW+&WIDTH) THEN GROUP=NN;
   NN+1;
   %LET LOW=%SYSEVALF(&LOW+&WIDTH);
  %END;
  DROP NN;
 PROC PRINT;
%MEND;

DATA JIM;
 INPUT X @@;
CARDS;
100 45 52 45 49 3 12 34 120 4 89 93
%GROUP3(DATA1=OUT,DATA0=JIM,VAR=X,LOW=0.1,HIGH=150.3,WIDTH=25.5);
PROC PRINT;
PROC FREQ DATA=OUT; TABLES GROUP;
RUN;