Hi, Ian and mavens and gurus,

Wow! As always, I just learn a lot from Ian's thoughtful code and comments.

His final comment about whether we should use an extra parameter (X) got me thinking. I thought it was a good idea. And after some time, I came up with a little bit of generalization of the loop_through_months macro as in the below. The basic idea is: if we have to use an extra parameter, then let's make the full use of it.

Given the fact that my co-workers do not really appreciate it when I try to think :-), I am not really confident if this is a good idea (hopefully) or a terribly bad one. I really appreciate your comments. Thank you.

Cheers, Chang

macro -------------------------------------------------------- %macro forEach(unit=, from=, to=, invoke=);

%local &unit. start end next;

%let unit = %lowcase(%trim(%left(&unit.)));

%if %index(year month day, &unit.) %then %do;

%let start = %sysfunc(intnx(&unit., %sysfunc(inputn(&from.,date9.)),0)); %let end = %sysfunc(intnx(&unit., %sysfunc(inputn(&to. ,date9.)),0)); %let next = %nrstr(%sysfunc(intnx(&unit.,&&&unit..,0,e)));

%end; %else %if &unit.=number %then %do;

%let start = &from.; %let end = &to.; %let next = %nrstr(&&&unit..);

%end;

%do &unit. = %unquote(&start.) %to %unquote(&end.); %unquote(&invoke.); %let &unit. = %unquote(&next.); %end;

%mend forEach; --------------------------------------------------------------

usage examples (log outputs in comments) --------------------- %macro test(year=); %put ***year=&year.***; %mend test; %forEach( unit=year, from=20mar2000, to=23feb2002, invoke=%nrstr(%test(year=%sysfunc(putn(&year.,year4.)))) ); /* ***year=2000*** ***year=2001*** ***year=2002*** */

%macro test(month=); %put ***month=&month.***; %mend test; %forEach( unit=month, from=01dec1999, to=10feb2000, invoke=%nrstr(%test(month=%sysfunc(putn(&month.,yymmn6.)))) ); /* ***month=199912*** ***month=200001*** ***month=200002*** */

%macro test(day=); %put ***day=&day.***; %mend test; %forEach( unit=day, from=28feb2000, to=02mar2000, invoke=%nrstr(%test(day=%sysfunc(putn(&day.,worddatx.)))) ); /* ***day=28 February 2000*** ***day=29 February 2000*** ***day=1 March 2000*** ***day=2 March 2000*** */

%macro test(number=); %put ***number=&number.***; %mend test; %forEach( unit=number, from=1, to=3, invoke=%nrstr(%test(number=&number)) ); /* ***number=1*** ***number=2*** ***number=3*** */ --------------------------------------------------------------

WHITLOI1@WESTAT.COM (Ian Whitlock) wrote in message news:<569DFDF32A05FC41A33DAA026649A18B08007F@REMAILW2K2>... > Doug, > > I would simplify and speed things up with SAS dates. Following Dennis' > suggestion and using > > %macro loop_through_months(startmon=, endmon=, sas_code_to_loop=); > > %local mon ; > > %do mon = %sysfunc(inputn(01&startmon,date9.)) > %to %sysfunc(inputn(01&endmon,date9.)) ; > > %unquote (&sas_code_to_loop)(mon=&mon) > > %let mon = %sysfunc(intnx(month,&mon,0,e)) ; > %end; > %mend loop_through_months; > > %macro test_macro(mon=); > %put ====> test_macro executing, > curr_yyyymm=%sysfunc(putn(&mon,yymmn6.)) ; > %mend test_macro ; > > > %loop_through_months(startmon=dec2002, > endmon=feb2003, > sas_code_to_loop=%nrstr(%test_macro)) > > Some comments are in order. With all those function calls, is it really > faster? Yes functions have been implemented very efficiently in comparison > with macro code. Why use the end of the month in the incrementation? > Because the iterative loop will add 1 bringing the date to the first of the > month. Why not use %BY 0? Because some Institute programmer checks your > code and refuses to allow %BY 0. > > Should one have the hidden parameter MON? It is questionable. It could be > left out, but my conscience won't let me call macros without passing > parameters. Why didn't I simply make the call > > %loop_through_months(startmon=dec2002, > endmon=feb2003, > sas_code_to_loop=%nrstr(%test_macro(mon=&mon)) > > I didn't want to burden your call with my conscience. Actually this form > may casue more problems than it is worth. I probably would change the call > the design to > > %macro loop_through_months(x= ,startmon=, endmon=, sas_code_to_loop=); > > %local &x ; > > %do &x = %sysfunc(inputn(01&startmon,date9.)) > %to %sysfunc(inputn(01&endmon,date9.)) ; > > > %unquote (&sas_code_to_loop) > > %let &x = %sysfunc(intnx(month,&&&x,0,e)) ; > %end; > %mend loop_through_months; > > %macro test_macro (mon=mon); > %put ====> test_macro executing, > curr_yyyymm=%sysfunc(putn(&mon,yymmn6.)) ; > %mend test_macro ; > > options nomlogic; > %loop_through_months(x=mon, > startmon=dec2002, > endmon=feb2003, > sas_code_to_loop=%nrstr(%test_macro(mon=&mon))) > > Here the parameter, X, allows the user to name the index and then to pass > the required value. Is it worth it? I still am not sure, but it allows the > user to name the index and to pass the value of that index as a parameter. > > > IanWhitlock@westat.com > -----Original Message----- > From: Doug Zirbel [mailto:doug_zirbel@HOTMAIL.COM] > Sent: Wednesday, September 24, 2003 12:56 PM > To: SAS-L@LISTSERV.UGA.EDU > Subject: Nested macro question for mavens and gurus > > > I wrote a macro which loops through "months", each iteration incrementing a > YYYYMM macro variable by 1 month. I want to pass that &YYYYMM to another > macro nested within the loop, but it of course is not cooperating. > > So how do I pass a macro variable created with a %LET to a macro as its > macro parameter? > > Here's the code: > > options nocenter mprint mlogic; > %global curr_yyyymm; > %let curr_yyyymm=; > > /*******************************************/ > /* This is the test macro (with a parameter) to > /* be nested into the macro loop in the next > /* macro. > /*******************************************/ > %macro test_macro; > %put ====> test_macro executing, curr_yyyymm=&curr_yyyymm; %mend; > > > /*******************************************************/ > /* This is the macro that loops through > /* "months" creating a new macro var "curr_yyyymm" > /* which is incremented by 1 month each iteration. > /* Right after it is incremented, it is to pass > /* that macro var to the nested macro. > /*******************************************************/ > %macro loop_through_months(start_yyyymm=, end_yyyymm=, sas_code_to_loop=); > > %let curr_yyyymm = &start_yyyymm; > > /********************************************** > /* Loop, from starting YYYYMM to ending YYYYMM > /* incrementing at the bottom. "DO UNTIL" > /* does its T/F test at the bottom of the loop. > /**********************************************/ > %do %until (&curr_yyyymm > &end_yyyymm); > %put curr_yyyymm=&curr_yyyymm; > /*******************************************/ > /* This macro var holds the test_macro to be > /* passed to the loop and to then be > /* executed before the next loop interation. > /*******************************************/ > &&sas_code_to_loop; > > /*******************************************/ > /* Increment from December (12) to January (01) > /* if necessary after calling nested macro > /*******************************************/ > %if %substr(&curr_yyyymm,5,2) = 12 %then %do; > %let curr_yyyy=%eval(%substr(&curr_yyyymm,1,4) + 1); > %let curr_mm = 01; > %let curr_yyyymm=&curr_yyyy.&curr_mm; > %end; > > /*******************************************/ > /* Increment from one month # to the next # > /* after calling nested macro > /*******************************************/ > %else %do; > %let curr_yyyymm=%eval(&curr_yyyymm + 1); > %end; > > %end; > %mend loop_through_months; > > %loop_through_months(start_yyyymm=200212, > end_yyyymm=200302, > sas_code_to_loop=%test_macro);