topic Re: want to write to global dataset from a macro(but it is erasing previous writes) in SAS Programming

want to write to global dataset from a macro(but it is erasing previous writes)

kashili — Wed, 20 Feb 2013 01:57:02 GMT

I have a macro which processes a dataset. I want to preserve the final outcome of this processing. So I am writing the final outcome to a global dataset(I could not think of any other alternative in SAS to make macro preserve the final outcome). This works good if I call macro once. However when I call macro more than once, only the last write is preserved(apparently previous writes are erased and I am preserved with only 1 final outcome in global dataset).

Assuming writing to global dataset is preferred way to preserve the final outcome of a macro, how can I RETAIN the writes to global dataset (instead of overwriting the previous content and preserving only 1 write in global dataset). Here is SAS snippet I am using..thank you

%macro LMGenerate(mymktdata,yeartag);

data &mymktdata.highliquidity;

*blah blah;

run;

data &mymktdata.lowliquidity;

*blah blah;

run;

*this is basically difference of above 2 datasets

data liquiditypremiums;
update &mymktdata.lowliquidity(in = a) &mymktdata.highliquidity(in =b);
by year;

if a & b then
do;
netpremium=lowliquiditytotal-highliquiditytotal;
output;
end;

run;

%mend LMGenerate;

*global data;

data liquiditypremiums;
run;

%LMGenerate(yr2010mktdata,2010 )
%LMGenerate(yr2011mktdata,2011 )

Re: want to write to global dataset from a macro(but it is erasing previous writes)

Linlin — Wed, 20 Feb 2013 02:24:41 GMT

Hi ,

try adding another macro variable:

%macro LMGenerate(mymktdata,yeartag,dsn);

data &mymktdata.highliquidity;

*blah blah;

run;

data &mymktdata.lowliquidity;

*blah blah;

run;

*this is basically difference of above 2 datasets

data &dsn._ liquiditypremiums;
update &mymktdata.lowliquidity(in = a) &mymktdata.highliquidity(in =b);
by year;

if a & b then
do;
netpremium=lowliquiditytotal-highliquiditytotal;
output;
end;

run;

%mend LMGenerate;

%LMGenerate(yr2010mktdata,2010,aaa )
%LMGenerate(yr2011mktdata,2011,bbb )

Re: want to write to global dataset from a macro(but it is erasing previous writes)

Tom — Wed, 20 Feb 2013 03:53:06 GMT

Not sure what you mean by a "global" dataset. You only seem to be creating WORK datasets.

If you want to append results to a dataset you might want to look at PROC APPEND.

Here is a trivial example.

%macro xx(value);

* Calculate new values ;

data new;

x=&value;

run;

proc append base=global data=new force;

run;

%mend xx;

%xx(1);

%xx(2);

proc print data=global;

run;

Re: want to write to global dataset from a macro(but it is erasing previous writes)

UrvishShah — Wed, 20 Feb 2013 04:29:52 GMT

Hello,

By default, SAS will replace the dataset if you supply the same name in your DATA statement that you named in your UPDATE, SET or MERGE statement...So here when you call the macro more than once, the you lose the prior update and finally you only have one dataset which overwrite the prior datasets...

I think in this case, use GENMAX = n option in data step...

%macro LMGenerate(mymktdata,yeartag);

data &mymktdata.highliquidity;

*blah blah;

run;

data &mymktdata.lowliquidity;

*blah blah;

run;

*this is basically difference of above 2 datasets

data liquiditypremiums (genmax = 3);
update &mymktdata.lowliquidity(in = a) &mymktdata.highliquidity(in =b);
by year;

if a & b then
do;
netpremium=lowliquiditytotal-highliquiditytotal;
output;
end;

run;

%mend LMGenerate;

*global data;

data liquiditypremiums;
run;

%LMGenerate(yr2010mktdata,2010 )
%LMGenerate(yr2011mktdata,2011 )

Thanks,

Urvish

Re: want to write to global dataset from a macro(but it is erasing previous writes)

kashili — Wed, 20 Feb 2013 16:57:01 GMT

Hello Linlin

what is 'aaa' and 'bbb'? Not sure how to fit in macro variable here (I am newbie..).

I have a dataset outside macro and I need my macro to append some values to this dataset (so that I can do post processing after all macros are executed).

thank you

Re: want to write to global dataset from a macro(but it is erasing previous writes)

Linlin — Wed, 20 Feb 2013 18:35:23 GMT

Hi,

try the code below to see if you get what you want (repace the RED part with your real dataset name, the dataset you want to add obsevations on):

%macro LMGenerate(mymktdata,yeartag);
data &mymktdata.highliquidity;
*blah blah;
run;

data &mymktdata.lowliquidity;
*blah blah;
run;

*this is basically difference of above 2 datasets
data _&mymktdata;
update &mymktdata.lowliquidity(in = a) &mymktdata.highliquidity(in =b);
by year;
if a & b then
do;
netpremium=lowliquiditytotal-highliquiditytotal;
output;
end;
run;

%mend LMGenerate;

%LMGenerate(yr2010mktdata,2010 )
%LMGenerate(yr2011mktdata,2011 )
*global data;
data want;
set your_global_dataset_name _:;
run;