Hi,
could some one please let me know how to adjust the following code to calculate WEEKLY VARIANCE ? the code below does it for monthly variance.
Data set is attached.
thanks.
data test;
infile "F:\data\residuals.csv" DSD MISSOVER;
input date :MMDDYY9. lnprices residual;
format date mmddyy10.;
run;
/* calculate monthly variance for all variables;*/
proc summary data=test nway;
class date;
var residual;
output out=month_var (drop=_:) var= ;
format date monyy.;
run;
/* rearrange data for by-group processing in GPLOT;*/
proc transpose data=month_var out=tmonth_var (rename=(col1=var));
by date;
format date monyy.;
run;
/*Graphing*/
proc sort data=tmonth_var;
by _name_ date;
run;
options validvarname=upcase;
goptions ftext='Arial' htext=2 gunit=pct;
symbol1 v=dot i=join;
axis1 label=(angle=90 "Monthly Variance");
title h=4 "Variance by Month for:1997-2005";
footnote j=right "Source: Henry Hub";
proc gplot data=tmonth_var;
plot var*date/vaxis=axis1;
by _name_ ;
run;
quit;
Instead of this in PROC SUMMARY
format date monyy.;
you want to add a week variable in data test;
You can use the week function and the year function to create a variable like this
week=cats(year(date),'W',week(date));
Change the format applied to your data to be a weekly format rather than monyy., I aligned mine to the beginning of the week but something similar can be done for end of the week if required.
%macro get_weekdate_fmt;
proc format;
value weekdate_fmt
%do k=0 %to 3000;
%eval(2+&k*7) - %eval(2+&k*7+6)=%sysfunc(putn(%eval(2+&k*7), date.))
%end;;*need two semicolons to end properly;
run;
%mend get_weekdate_fmt;
I had some help with creating one here, see code above.
http://listserv.uga.edu/cgi-bin/wa?A2=ind1211b&L=sas-l&F=&S=&P=4762
Or a custom format using the date directives such as:
proc format library=work;
picture MyWeekFmt (min=8 max=8)
low-high = '%Y %0U' (datatype=date);
run;
Note that the directives ARE CASE SENSITIVE. The U could be W or V for different definitions of start week.
data _null_;
x= '23Feb2011'd;
put x= MyWeekFmt.;
run;
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