%macro SQUEEZE( DSNIN /* name of input SAS dataset */ , DSNOUT /* name of output SAS dataset */ ) ; /* PURPOSE: create SAS dataset &DSNOUT using LENGTH */ /* statement for numeric vars that optimizes the */ /* variable to the fewest # of bytes needed */ /* to maintain the accuracy of the values */ /* contained in the variable */ /* */ /* macro variable SQZLENTH is created which is */ /* then invoked in a subsequent data step */ /* */ /* NOTE: only numeric variables are processed */ /* */ /* EXAMPLE OF USE: */ /* %SQUEEZE( DSNIN, DSNOUT ) */ %global SQUEEZE ; %local I ; %put *============================================* ; %put | Beginning to SQUEEZE. | ; %put | Please be patient because this process may | ; %put | require a lot of execution time. | ; %put *============================================* ; %macro PUTNAME ; /* PURPOSE: put variable names into SAS source code */ %do I = 1 %to &VAR_N ; &&VAR&I %end ; %mend PUTNAME ; %macro SQZLENTH ; /* PURPOSE: create variable name-variable length pairs */ %do I = 1 %to &VAR_N ; &&VAR&I &&VLEN&I %end ; %mend SQZLENTH ; /***********************************************************/ /* ensure that DSNIN not same as DSNOUT */ /***********************************************************/ %if "&DSNIN" = "&DSNOUT" %then %do ; %put *================================================* ; %put | ERROR from SQUEEZE: | ; %put | Input Dataset has same name as Output Dataset. | ; %put | Execution terminating forthwith. | ; %put *================================================* ; %goto L9999 ; %end ; %let VAR_N = 0 ; /*##########################################################*/ /* begin executable code */ /*##########################################################*/ proc contents data=&DSNIN memtype=data noprint out=_cntnts_ ; run ; data _null_ ; set _cntnts_ ; if type = 1 ; var_no + 1 ; /* create macro var containing final # of macro vars */ call symput( 'VAR_N', left( put( var_no, 4. ) ) ) ; run ; /* in case there are NO numeric vars in dataset, */ /* stop further processing */ %if "&VAR_N" = "0" %then %do ; %put *==================================* ; %put | ERROR from SQUEEZE: | ; %put | No numeric variables in dataset. | ; %put | Execution terminating forthwith. | ; %put *==================================* ; %goto L9999 ; %end ; /* put global macro names into environment for later retrieval */ %do I = 1 %to &VAR_N ; %global VAR&I VLEN&I ; %end ; /* create macro vars containing variable name */ /* process variables of numeric type only */ data _null_ ; set _cntnts_ ; if type = 1 ; var_no + 1 ; call symput( 'VAR' || left( put( var_no, 5. )), name ) ; run ; /* compute min # bytes (3 = min length, for */ /* portability over platforms) */ data _null_ ; set &DSNIN end=lastobs ; array _length_ ( &VAR_N ) 3 _temporary_ ; if _n_ = 1 then do i = 1 to &VAR_N ; _length_( i ) = 3 ; end ; %do I = 1 %to &VAR_N ; if &&VAR&I ne . then do ; if &&VAR&I ne trunc( &&VAR&I, 7 ) then _length_( &I ) = max( _length_( &I ), 8 ) ; else if &&VAR&I ne trunc( &&VAR&I, 6 ) then _length_( &I ) = max( _length_( &I ), 7 ) ; else if &&VAR&I ne trunc( &&VAR&I, 5 ) then _length_( &I ) = max( _length_( &I ), 6 ) ; else if &&VAR&I ne trunc( &&VAR&I, 4 ) then _length_( &I ) = max( _length_( &I ), 5 ) ; else if &&VAR&I ne trunc( &&VAR&I, 3 ) then _length_( &I ) = max( _length_( &I ), 4 ) ; end ; %end ; if lastobs then do ; %do I = 1 %to &VAR_N ; call symput( "VLEN&I", put( _length_( &I ), 1. )) ; %end ; end ; run ; proc datasets nolist ; delete _cntnts_ ; run ; /* initialize SQZLENTH global macro var */ %let SQZLENTH = LENGTH ; %do I = 1 %to &VAR_N ; %if "&&VLEN&I" ne "" %then %let SQZLENTH = &SQZLENTH %qtrim( &&VAR&I ) &&VLEN&I ; %end ; /* create global SQZLENTH variable containing */ /* var name-var length info */ %let SQZLENTH = &SQZLENTH %str( ; ) ; /* apply SQZLENTH to incoming data, create output dataset */ data &DSNOUT ; set &DSNIN ; &SQZLENTH run ; %L9999: %mend SQUEEZE ;