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Date:         Thu, 9 Dec 2004 19:59:35 +0000
Reply-To:     iw1junk@COMCAST.NET
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Ian Whitlock <iw1junk@COMCAST.NET>
Subject:      Re: How to define a global determistic variable without using
              Macro
Comments: cc: Fred <ieaggie2002@gmail.com>

Fred,

You haven't made clear what your objection to macro is. All of the suggestions I have seen so far involve some use of macro and may limit your use of the constant. If your objection is that macro variables are easily changed, then you might consider something like

%macro g1 ; hello %mend ; data _null_ ; put "%g1" ; run ;

Of course one can still redefine macros, but one is less likely to change macro definitions than variable values. This could be improved to house all global constants and take a parameter to specify which one is returned. In fact this is how I usually avoid global macro variables.

If you really want to avoid all SAS macro tools then you could use the following idea.

/* code to process program on CARDS4 using global constants g1 g2 */ filename temp temp ; data _null_ ; /* global constants - case of names must match code */ g1 = 5 ; g2 = "Hello" ; Length line $ 200 ;

input line $char80. ; do while ( index ( line, "#g1" ) > 0 ) ; line = tranwrd ( line , "#g1" , trim(put(g1,best32. -l))) ; end ; do while ( index ( line, "#g2" ) > 0 ) ; line = tranwrd ( line , "#g2" , trim(left(g2))) ; end ; file temp ; put line ; cards4 ; /* this is the program */ data w#g1 ; x = #g1 ; y = "#g2" ; put _all_ ; run ; title "#g2: Data set is w#g1" ; proc print data = w#g1 ; run ; ;;;;

/* now execute the processed program */ %inc temp / source2 ;

In a somewhat more general and realistic setting you would use fileref other than CARDS4 for your "large program". At the expense of more complexity you can design the above step to accept global constants announced as such within the program to be executed. This would allow the use of an arbitrary list of global constants and more stable processing code. (I actually did this as a Coder's Corner paper for NESUG some years ago.)

Of course, I have simply implemented a crude macro processor so I haven't escaped the concept of macro (i.e. preprocessing code), I have merely avoided all use of the SAS macro facility. On the other hand, the concept of global constant is not built into SAS and I very much doubt that one can achieve it in SAS without some form of preprocessing SAS code. So what is your objection to using macro?

Ian_Whitlock@comcast.net =================================== Date: Wed, 8 Dec 2004 14:14:00 -0500 Reply-To: Fred <ieaggie2002@gmail.com> Sender: "SAS(r) Discussion" From: Fred <ieaggie2002@GMAIL.COM> Subject: How to define a global determistic variable without using Macro Content-Type: text/plain; charset=US-ASCII Hi, all I wrote a long SAS code, and after that I realized I need to define a global determistic variable to replace a constant value in the code. However, I dont want to use MACRO to define this variable. For example, I want the code to look like: myvariable = constant; * this constant can be changed if needed. data xx; statement; run; other proc statements involving the reference of "myvariable"; ... So is there some easy way to add this variable assignment command? Thanks for your point. Fred


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