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Professor Diana Kornbrot University of Hertfordshire College Lane, Hatfield, AL10 9AB, UK Email: d.e.kornbrot@herts.ac.uk Blended Learning Unit voice: +44[0]170 728 4313 fax: +44[0] 170 728 4320 Psychology voice: +44[0]170 728 4626 fax: +44[0]170 728 5073

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> -----Original Message----- > From: SPSSX(r) Discussion [mailto:SPSSX-L@LISTSERV.UGA.EDU] > On Behalf Of David Wasserman > Sent: 13 June 2006 20:22 > To: SPSSX-L@LISTSERV.UGA.EDU > Subject: Re: Can't !LET & VAR LABELS be used in DO IF...ELSE > IF... END IF structures in MACROs? revisited > > As I understand it, macros have three stages: definition, > obviously, between DEFINE and !ENDDEFINE statements, > expansion, and execution. Both expansion and execution take > place when the macro is called, but are clearly a two-step > process. When the macro you have presented expands, > everything that is not a macro command, keyword, or argument > is still just a string. > During the expansion, the macro commands, keywords and > arguments are resolved, and essentially disappear, replaced > by the strings to which they resolve. The expansion happens > only once, and while it is happening there are no variable > values. Therefore, a DO IF structure, which depends on the > existence of variable values, which change as often as there > are cases, cannot control the execution of a !LET command. > All the !LET commands expand before the resulting strings are > treated as SPSS syntax. The end result is that the last !LET > command used to assign a value to a macro keyword is the !LET > command that gives that keyword the string content it has > when the macro expanded output executes. Your example shows > that: only the last !LET command appears to work. > > I hope that helps. > > David Wasserman > Custom Data Analysis and SPSS Programming > > ----- Original Message ----- > From: "Marta García-Granero" <biostatistics@terra.es> > Newsgroups: bit.listserv.spssx-l > To: <SPSSX-L@LISTSERV.UGA.EDU> > Sent: Tuesday, June 13, 2006 12:45 PM > Subject: Can't !LET & VAR LABELS be used in DO IF...ELSE > IF... END IF structures in MACROs? revisited > > > > Hi everybody: > > > > Since my first post presented only part of a very long > MACRO, perhaps > > the problem can't be easily reproduced by other people. > That's why I > > have written a tiny demo that shows the problem: > > > > DATA LIST FREE/testvar. > > BEGIN DATA > > 1 1 1 2 2 2 3 3 3 > > END DATA. > > FORMAT testvar (F8). > > > > DEFINE DEMOTEST(method=!TOKENS(1)). > > DO IF !method EQ 1. > > - VAR LABEL testvar 'Method #1 was selected'. > > - !LET !label_1=!UNQUOTE('1-A'). > > - !LET !label_2=!UNQUOTE('1-B'). > > - !LET !label_3=!UNQUOTE('1-C'). > > ELSE IF !method EQ 2. > > - VAR LABEL testvar 'Method #2 was selected'. > > - !LET !label_1=!UNQUOTE('2-A'). > > - !LET !label_2=!UNQUOTE('2-B'). > > - !LET !label_3=!UNQUOTE('2-C'). > > ELSE. > > - VAR LABEL testvar 'Other method was selected'. > > - !LET !label_1=!UNQUOTE('Other-A'). > > - !LET !label_2=!UNQUOTE('Other-B'). > > - !LET !label_3=!UNQUOTE('Other-C'). > > END IF. > > DO IF $casenum EQ 1. > > - ECHO "The method used was:". > > - ECHO !QUOTE(!method). > > END IF. > > VALUE LABEL testvar 1 !QUOTE(!QUOTE(!label_1)) > > 2 !QUOTE(!QUOTE(!label_2)) > > 3 !QUOTE(!QUOTE(!label_3)). > > FREQUENCIES > > VARIABLES=testvar. > > !ENDDEFINE. > > > > DEMOTEST method=1. > > DEMOTEST method=2. > > > > As you can see if you run this example, the last instance > of the list > > of DO IF... ELSE IF... ELSE is always selected. > > > > Can anybody enlighten me? > > > > Thanks, > > Marta mailto:biostatistics@terra.es > > > > (Anyway: my Meta-analysis MACRO is written and working properly - > > using a long workaround to the above mentioned problem - > and available > > on request). > > > >