SAS Macro for multiple datasets - sas

I am new to SAS. I have 12(Monthly data) data sets in a folder.
Names of data sets are:
201401
201402
201403
...
201411
201412
Each data contain 10 Variables. Variable names are same for all data.
I want only 3 Variables among 10 and rename data by new_201401 and so on.
I am trying it manually by using Keep Var1 Var2 Var3; but is there any easy way or macro so we can make it fast? Thanks in advance.

I think this will do the trick:
%macro keep(table,var1,var2,var3,set);
data &table (keep=&var1 &var2 &var3);
set &set;
run;
%mend keep;

You can rename them using the following macro (note: the %if conditions are just split out to include a leading 0 for single digit months):
%macro monthly(year=,prefix=) ;
%do i=1 %to 2 ;
%if %eval(&i<10) %then Data_&year.0&i=&prefix&i ;
%else Data_&year&i=&prefix&i ;
%end ;
%mend monthly ;
You can then then for example pass these values into proc datasets for whatever years you need:
proc datasets library=work ;
change %monthly(year=2014,prefix=new_) %monthly(year=2015,prefix=new2_);
run ;

Related

How to run part of macro based on number of observations in work file in SAS

I'm pretty new to doing macros on SAS so apologies in advance if my questions seems basic.
I'm looking to execute part of a macro if there are a minimum number of observations found in temporary work file.
If there are a minimum number of observations, the macro should execute a proc export of that temporary work file, otherwise it will just produce an error message on the log.
I'm not sure what I'm doing wrong, the temporary work file has more than 1 observation and I want the macro to run, however it produces the error message as if it has less than the minimum.
Below is the code that I've created so far - any help you have to offer will be greatly welcomed.
data original_data;
set data.dataset;
keep column1 column2 column3 ;
run;
%macro test_macro;
%let dsid=%sysfunc(open(work.original_data));
%let nobs=%sysfunc(attrn(&dsid,nobs));
%let dsid=%sysfunc(close(&dsid));
%if &nobs >1 %then %do;
%put ERROR: No observations counted;
%return
%end
%else %do;
proc export data=submissions
outfile='C:\Users\myusername\Desktop\test.csv'
DBMS=csv replace;
run;
%end;
%mend test_macro;
%test_macro
Missing semicolons on RETURN and END statements
Logic is reversed. You're putting the error message if you have more than one observation. Flip your code so that you export if you have more than one observation.
options mprint symbolgen;
%macro test_macro;
%let dsid=%sysfunc(open(work.original_data));
%let nobs=%sysfunc(attrn(&dsid, nobs));
%let dsid=%sysfunc(close(&dsid));
%put &nobs;
*if more than one observation;
%if &nobs > 1 %then
%do;
proc export data=sashelp.class outfile='/home/fkhurshed/test.csv' DBMS=csv
replace;
run;
%end;
%else
%do;
%put ERROR: No observations counted;
%return;
%end;
%mend test_macro;
%test_macro;

sas macro loop to rename variable

Hi I am trying to rename variables using SAS Macro loop.
%Let t1=12Mth;
%Let t2=20;
%Let t3=30;
%Let t4=40;
%Let t5=50;
%Let t6=60;
%macro Re(time);
%Do I = 1 %to &time.;
data MilkNew;
set Milk;
rename MT&&t&I..Sp=MTSp&&t&I.;
run;
%end;
%mend Re;
%Re(6)
This loop is mean to rename MT...Sp to MTSp.... Eg:MT20SP to MTSp20.
When I run my loop, there was no error but the variable names were not changed in MilkNew at all.
Where does the problem come? Thanks!
If the only purpose of the macro is to rename the variables in the data set, then why read the data with a set statement. Your data set is probably really small so you don't even realize the inefficiency of doing that. Instead use the modify statement in proc datasets to accomplish the same thing, but more efficiently. Here's an alternative macro for you.
%macro renamevar(dsname, time);
%local lib ds i;
%let lib = %sysfunc(coalescec(%scan(&dsname, -2, %str(.)), work));
%let ds = %scan(&dsname, -1, %str(.));
proc datasets lib=&lib nolist;
modify &ds;
rename
%do i = 1 %to &time;
mt&&t&i..Sp=MTSp&&t&i.
%end;
;
quit;
%mend;
%renamevar(milk, 6);
Here's the log after the macro call:
NOTE: Renaming variable mt12MthSp to MTSp12Mth.
NOTE: Renaming variable mt20Sp to MTSp20.
NOTE: Renaming variable mt30Sp to MTSp30.
NOTE: Renaming variable mt40Sp to MTSp40.
NOTE: Renaming variable mt50Sp to MTSp50.
NOTE: Renaming variable mt60Sp to MTSp60.
NOTE: MODIFY was successful for WORK.MILK.DATA.
NOTE: PROCEDURE DATASETS used (Total process time):
real time 0.00 seconds
cpu time 0.01 seconds
You should move the loop so that it only generates just the RENAME statement (or even just the old=new name pairs). What is happening now is that you keep overwriting MilkNew so only the last RENAME has any effect.
%macro Re(time);
data MilkNew;
set Milk;
%do I = 1 %to &time.;
rename MT&&t&I..Sp=MTSp&&t&I.;
%end;
run;
%mend Re;
%Re(6)
You should have seen the last variable name in the loop (so the 6th) changed. That's because you repeated the same data step with the same source dataset but a different destination - so each time you 'forgot' the changes made in the earlier step.
So, this would've worked, though I'll get in a minute to why this isn't a good way to do this.
%Let t1=12Mth;
%Let t2=20;
%Let t3=30;
%Let t4=40;
%Let t5=50;
%Let t6=60;
%macro Re(time);
%Do I = 1 %to &time.;
data Milk;
set Milk;
rename MT&&t&I..Sp=MTSp&&t&I.;
run;
%end;
%mend Re;
data milk;
input
MT12mthSP
MT20SP
MT30SP
MT40SP
MT50SP
MT60SP
;
datalines;
12 20 30 40 50 60
;;;;
run;
%Re(6)
Here I had it make all changes to Milk and save them back in that dataset. If you want to preserve Milk then first make Milk_New then have that in both set and data statements.
Second, you should not do a new data step for each change. Macros don't have to have a data step in them; they can be run inside the datastep.
So for example:
%macro Re(time);
%Do I = 1 %to &time.;
rename MT&&t&I..Sp=MTSp&&t&I.;
%end;
%mend Re;
data milk_new;
set milk;
%Re(6);
run;
Even better would be generating this list outside of a macro entirely - look up "generating code SAS" for suggestions on that.
If you didn't see any renames at all, you also may have an issue where a label is present on the column(s). That won't affect your usage of the variable name, but it will make it confusing. Use
label _all_;
Or include a label-clearing statement (label <varname>; where you pop in the same variable name as the original variable name before rename) inside your macro loop to fix that.

List only the column names of a dataset

I am working on SAS in UNIX env and I want to view only the column name of a dataset. I have tried proc contents and proc print but both of them list a lot of other irrevelant information that I do not want as it fills up my putty screen and the information ultimately is lost.
I also tried to get this thing frm the sas metadata but that is not working either.
I tried :
2? proc sql;
select *
from dictionary.tables
where libname='test' and memname='sweden_elig_file_jul';
quit;
5?
NOTE: No rows were selected.
6?
NOTE: PROCEDURE SQL used (Total process time):
real time 0.27 seconds
cpu time 0.11 seconds
You're using the wrong dictionary table to get column names...
proc sql ;
select name
from dictionary.columns
where memname = 'mydata'
;
quit ;
Or using PROC CONTENTS
proc contents data=mydata out=meta (keep=NAME) ;
run ;
proc print data=meta ; run ;
Here's one I've used before to get a list of columns with a little bit more information, you can add the keep option as in the previous answer. This just demonstrates how to create a connection to the metadata server, in case that is useful to anyone viewing this post.
libname fetchlib meta
library="libraryName" metaserver="metaDataServerAddress"
password="yourPassword" port=1234
repname="yourRepositoryName" user="yourUserName";
proc contents data=fetchlib.YouDataSetName
memtype=DATA
out=outputDataSet
nodetails
noprint;
run;
For a pure macro approach, try the following:
%macro mf_getvarlist(libds
,dlm=%str( )
)/*/STORE SOURCE*/;
/* declare local vars */
%local outvar dsid nvars x rc dlm;
/* open dataset in macro */
%let dsid=%sysfunc(open(&libds));
%if &dsid %then %do;
%let nvars=%sysfunc(attrn(&dsid,NVARS));
%if &nvars>0 %then %do;
/* add first dataset variable to global macro variable */
%let outvar=%sysfunc(varname(&dsid,1));
/* add remaining variables with supplied delimeter */
%do x=2 %to &nvars;
%let outvar=&outvar.&dlm%sysfunc(varname(&dsid,&x));
%end;
%End;
%let rc=%sysfunc(close(&dsid));
%end;
%else %do;
%put unable to open &libds (rc=&dsid);
%let rc=%sysfunc(close(&dsid));
%end;
&outvar
%mend;
Usage:
%put List of Variables=%mf_getvarlist(sashelp.class);
Returns:
List of Variables=Name Sex Age Height Weight
source: https://github.com/sasjs/core/blob/main/base/mf_getvarlist.sas
proc sql;
select *
from dictionary.tables
where libname="TEST" and memname="SWEDEN_ELIG_FILE_JUL";
quit;

"For in" loop equivalent in SAS 9.3

I'm searching for a while an equivalent of the for in loop (like in Python or in R) in SAS 9.3 macro language. The DO loop seem's to be the solution but did't work exactly as I want.
I founded a way to do it in a data step with a DO loop but it don't work with the macro language.
For example, in a data step, this code is working :
DATA _NULL_;
DO i = 1,3,5,9;
PUT i;
END;
RUN;
And then the log prompt as expected :
1
3
5
9
When I try to do the same with an %DO loop in a Macro, I have an error.
%MACRO test();
%DO i = 1,2,4,9 ;
%PUT i = &i;
%END;
%MEND;
%test();
The log promp these messages :
ERROR: Expected %TO not found in %DO statement.
ERROR: A dummy macro will be compiled
I'm quite new in SAS and stackoverflow so I hope my question is no too stupid. It's so simple to do this in Python and R then it must have a simple way to do it in SAS.
Thank's for help - J. Muller
The closest I've ever come across to this pattern in SAS macro language is this:
%MACRO test();
%let j=1;
%let vals=1 2 4 9;
%do %while(%scan(&vals,&j) ne );
%let i=%scan(&vals, &j);
%put &i;
%let j=%eval(&j+1);
%end;
%MEND;
%test();
(Warning: untested, as I no longer have a SAS installation I can test this out on.)
You can certainly get around it this way:
options mindelimiter=,;
options minoperator;
%MACRO test();
%DO i = 1 %to 9 ;
%if &i in (1,2,4,9) %then %do;
%PUT i = &i;
%END;
%end;
%MEND;
%test();
However, I think you can usually avoid this sort of call by executing your macro multiple times rather than attempting to control the loop inside the macro. For example, imagine a dataset and a macro:
data have;
input x;
datalines;
1
2
4
9
;;;;
run;
%macro test(x);
%put &x;
%mend test;
Now you want to call %test() once for each value in that list. Okay, easy to do.
proc sql;
select cats('%test(',x,')') into :testcall separated by ' ' from have;
quit;
&testcall;
That works just as well as your %do in loop, except it's data driven, meaning if you want to change the calls you just change the dataset (or if your data changes, the call automatically changes!). In general, SAS is more effective when designed as data driven programming rather than as entirely written code.

How to detect how many observations in a dataset (or if it is empty), in SAS?

I wonder if there is a way of detecting whether a data set is empty, i.e. it has no observations.
Or in another saying, how to get the number of observations in a specific data set.
So that I can write an If statement to set some conditions.
Thanks.
It's easy with PROC SQL. Do a count and put the results in a macro variable.
proc sql noprint;
select count(*) into :observations from library.dataset;
quit;
There are lots of different ways, I tend to use a macro function with open() and attrn(). Below is a simple example that works great most of the time. If you are going to be dealing with data views or more complex situations like having a data set with records marked for deletion or active where clauses, then you might need more robust logic.
%macro nobs(ds);
%let DSID=%sysfunc(OPEN(&ds.,IN));
%let NOBS=%sysfunc(ATTRN(&DSID,NOBS));
%let RC=%sysfunc(CLOSE(&DSID));
&NOBS
%mend;
/* Here is an example */
%put %nobs(sashelp.class);
Here's the more complete example that #cmjohns was talking about. It will return 0 if it is empty, -1 if it is missing, and has options to handle deleted observations and where clauses (note that using a where clause can make the macro take a long time on very large datasets).
Usage Notes:
This macro will return the number of observations in a dataset. If the dataset does not exist then -1 will be returned. I would not recommend this for use with ODBC libnames, use it only against SAS tables.
Parameters:
iDs - The libname.dataset that you want to check.
iWhereClause (Optional) - A where clause to apply
iNobsType (Optional) - Either NOBS OR NLOBSF. See SASV9 documentation for descriptions.
Macro definition:
%macro nobs(iDs=, iWhereClause=1, iNobsType=nlobsf, iVerbose=1);
%local dsid nObs rc;
%if "&iWhereClause" eq "1" %then %do;
%let dsID = %sysfunc(open(&iDs));
%end;
%else %do;
%let dsID = %sysfunc(open(&iDs(where=(&iWhereClause))));
%end;
%if &dsID %then %do;
%let nObs = %sysfunc(attrn(&dsID,nlobsf));
%let rc = %sysfunc(close(&dsID));
%end;
%else %do;
%if &iVerbose %then %do;
%put WARNING: MACRO.NOBS.SAS: %sysfunc(sysmsg());
%end;
%let nObs = -1;
%end;
&nObs
%mend;
Example Usage:
%put %nobs(iDs=sashelp.class);
%put %nobs(iDs=sashelp.class, iWhereClause=height gt 60);
%put %nobs(iDs=this_dataset_doesnt_exist);
Results
19
12
-1
Installation
I recommend setting up a SAS autocall library and placing this macro in your autocall location.
Proc sql is not efficient when we have large dataset. Though using ATTRN is good method but this can accomplish within base sas, here is the efficient solution that can give number of obs of even billions of rows just by reading one row:
data DS1;
set DS nobs=i;
if _N_ =2 then stop;
No_of_obs=i;
run;
The trick is producing an output even when the dataset is empty.
data CountObs;
i=1;
set Dataset_to_Evaluate point=i nobs=j; * 'point' avoids review of full dataset*;
No_of_obs=j;
output; * Produces a value before "stop" interrupts processing *;
stop; * Needed whenever 'point' is used *;
keep No_of_obs;
run;
proc print data=CountObs;
run;
The above code is the simplest way I've found to produce the number of observations even when the dataset is empty. I've heard NOBS can be tricky, but the above can work for simple applications.
A slightly different approach:
proc contents data=library.dataset out=nobs;
run;
proc summary data=nobs nway;
class nobs;
var delobs;
output out=nobs_summ sum=;
run;
This will give you a dataset with one observation; the variable nobs has the value of number of observations in the dataset, even if it is 0.
I guess I am trying to reinvent the wheel here with so many answers already. But I do see some other methods trying to count from the actual dataset - this might take a long time for huge datasets. Here is a more efficient method:
proc sql;
select nlobs from sashelp.vtable where libname = "library" and memname="dataset";
quit;