Hi:
In addition to Scott's suggestions, investigate the SKIPMISS option with PROC GPLOT -- for example, in the data below, the month of June has an observation, but the value for EXPENSE is missing (.) and therefore, the SKIPMISS option tells PROC GPLOT that join should "skip" over the missing value with the line. If your data does not have an observation for June (for example), then the line would be drawn from May - July -- so you might have to put a "dummy" observation into your data for SKIPMISS to work, under that scenario.
cynthia
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** Missing Y Values;
data expense;
infile datalines;
input date : mmddyy10. expense dept $;
format date monyy5.;
return;
datalines;
01/15/2010 100000 Acct
02/15/2010 125000 Acct
03/15/2010 115000 Acct
04/15/2010 135000 Acct
05/15/2010 140000 Acct
06/15/2010 . Acct
07/15/2010 120000 Acct
08/15/2010 145000 Acct
09/15/2010 160000 Acct
10/15/2010 130000 Acct
11/15/2010 155000 Acct
12/15/2010 150000 Acct
;
run;
goptions reset=symbol;
symbol1 cv=blue value=dot i=join;
proc gplot data=work.expense;
plot expense * date / skipmiss;
run;
quit;
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