Need to set unknown amount of datasets together - sas

I have a macro that creates multiple datasets. The number of datasets depends on other factors and could be 0-X. I need to set all of these datasets together into one dataset to export.
%macro runpromo(setid=, title=, start=, end=, no=);
%get_offer_data(label=&title , start=date &start, end=date &end, rc=%quote(&setid), source=1);
data promo&no.;
length item_desc $50.0;
set edw_final;
run;
%mend runpromo;
data _null_;
set macros;
call execute('%runpromo(setid='||code||',title='||promo_title||',start ='||start_date||',end='||end_date||',no='||count||');');
run;
data all_promos;
length item_desc $50.0;
set promo1-promoX;
run;
I want to automate this code to run daily so I don't want to have to go in and update the dataset names each time.

Use a naming convention where each data set has the same prefix and goes to a single library. Then you can stack them easily at the end:
data want;
set prom:;
run;
The colon (:) acts as a wild card and all datasets with the prefix prom in the work library will be combined.

Why not just build the larger dataset as you go?
Macro Definition:
%macro runpromo(setid=, title=, start=, end=, no=);
%get_offer_data(label=&title,start=date &start,end=date &end,rc=%quote(&setid),source=1);
data promo_fix;
length item_desc $50;
set edw_final;
run;
proc append base=all_promos data=promo_fix force;
run;
%mend runpromo;
Program:
proc delete data=all_promos;
run;
data _null_;
set macros;
call execute(cats('%nrstr(%runpromo)'
,'(setid=',code
,',title=',promo_title
,',start =',start_date
,',end=',end_date
,',no=',count
,');'
));
run;

Related

SAS-Creating Panel by several datasets

Suppose there are ten datasets with same structure: date and price, particularly they have same time period but different price
date price
20140604 5
20140605 7
20140607 9
I want to combine them and create a panel dataset. Since there is no name in each datasets, I attempt to add a new variable name into each data and then combine them.
The following codes are used to add name variable into each dataset
%macro name(sourcelib=,from=,going=);
proc sql noprint; /*read datasets in a library*/
create table mytables as
select *
from dictionary.tables
where libname = &sourcelib
order by memname ;
select count(memname)
into:obs
from mytables;
%let obs=&obs.;
select memname
into : memname1-:memname&obs.
from mytables;
quit;
%do i=1 %to &obs.;
data
&going.&&memname&i;
set
&from.&&memname&i;
name=&&memname&i;
run;
%end;
%mend;
So, is this strategy correct? Whether are there a different way to creating a panel data?
There are really two ways to setup repeated measures data. You can use the TALL method that your code will create. That is generally the most flexible. The other would be a wide format with each PRICE being stored in a different variable. That is usually less flexible, but can be easier for some analyses.
You probably do not need to use macro code or even code generation to combine 10 datasets. You might find that it is easier to just type the 10 dataset names than to write complex code to pull the names from metadata. So a data step like this will let you list any number of datasets in the SET statement and use the membername as the value for the new PANEL variable that distinguishes the source dataset.
data want ;
length dsn $41 panel $32 ;
set in1.panel1 in1.panela in1.panelb indsname=dsn ;
panel = scan(dsn,-1,'.') ;
run;
And if your dataset names follow a pattern that can be used as a member list in the SET statement then the code is even easier to write. So you could have a list of names that have a numeric suffix.
set in1.panel1-in1.panel10 indsname=dsn ;
or perhaps names that all start with a particular prefix.
set in1.panel: indsname=dsn ;
If the different panels are for the same dates then perhaps the wide format is easier? You could then merge the datasets by DATE and rename the individual PRICE variables. That is generate a data step that looks like this:
data want ;
merge in1.panel1 (rename=(price=price1))
in1.panel2 (rename=(price=price2))
...
;
by date;
run;
Or perhaps it would be easier to add a BY statement to the data set that makes the TALL dataset and then transpose it into the WIDE format.
data tall;
length dsn $41 panel $32 ;
set in1.panel1 in1.panela in1.panelb indsname=dsn ;
by date ;
panel = scan(dsn,-1,'.') ;
run;
proc transpose data=tall out=want ;
by date;
id panel;
var price ;
run;
I can't comment on the SQL code but the strategy is correct. Add a name to each data set and then panel on the name with the PANELBY statement.
That is a valid way to achieve what you are looking for.
You are going to need 2 . in between the macros for library.data syntax. The first . is used to concatenate. The second shows up as a ..
I assume you will want to append all of these data sets together. You can add
data &going..want;
set
%do i=1 %to &obs;
&from..&&memname&i
%end;
;
run;
You can combine your loop that adds the names and that data step like this:
data &going..want;
set
%do i=1 %to &obs;
&from..&&memname&i (in=d&i)
%end;
;
%do i=1 %to &obs;
if d&i then
name = &&memname&i;
%end;
run;

proc report print null dataset

I have a null dataset such as
data a;
if 0;
run;
Now I wish to use proc report to print this dataset. Of course, there will be nothing in the report, but I want one sentence in the report said "It is a null dataset". Any ideas?
Thanks.
You can test to see if there are any observations in the dataset first. If there are observations, then use the dataset, otherwise use a dummy dataset that looks like this and print it:
data use_this_if_no_obs;
msg = 'It is a null dataset';
run;
There are plenty of ways to test datasets to see if they contain any observations or not. My personal favorite is the %nobs macro found here: https://stackoverflow.com/a/5665758/214994 (other than my answer, there are several alternate approaches to pick from, or do a google search).
Using this %nobs macro we can then determine the dataset to use in a single line of code:
%let ds = %sysfunc(ifc(%nobs(iDs=sashelp.class) eq 0, use_this_if_no_obs, sashelp.class));
proc print data=&ds;
run;
Here's some code showing the alternate outcome:
data for_testing_only;
if 0;
run;
%let ds = %sysfunc(ifc(%nobs(iDs=for_testing_only) eq 0, use_this_if_no_obs, sashelp.class));
proc print data=&ds;
run;
I've used proc print to simplify the example, but you can adapt it to use proc report as necessary.
For the no data report you don't need to know how many observations are in the data just that there are none. This example shows how I would approach the problem.
Create example data with zero obs.
data class;
stop;
set sashelp.class;
run;
Check for no obs and add one obs with missing on all vars. Note that no observation are every read from class in this step.
data class;
if eof then output;
stop;
modify class end=eof;
run;
make the report
proc report data=class missing;
column _all_;
define _all_ / display;
define name / order;
compute before name;
retain_name=name;
endcomp;
compute after;
if not missing(retain_name) then l=0;
else l=40;
msg = 'No data for this report';
line msg $varying. l;
endcomp;
run;

Set the labels of a SAS Dataset equal to their variable name

I'm working with a rather large several dataset that are provided to me as a CSV files. When I attempt to import one of the files the data will come in fine but, the number of variables in the file is too large for SAS, so it stops reading the variable names and starts assigning them sequential numbers. In order to maintain the variable names off of the data set I read in the file with the data row starting on 1 so it did not read the first row as variable names -
proc import file="X:\xxx\xxx\xxx\Extract\Live\Live.xlsx" out=raw_names dbms=xlsx replace;
SHEET="live";
GETNAMES=no;
DATAROW=1;
run;
I then run a macro to start breaking down the dataset and rename the variables based on the first observations in each variable -
%macro raw_sas_datasets(lib,output,start,end);
data raw_names2;
raw_names;
if _n_ ne 1 then delete;
keep A -- E &start. -- &end.;
run;
proc transpose data=raw_names2 out=raw_names2;
var A -- &end.;
run;
data raw_names2;
set raw_names2;
col1=compress(col1);
run;
data raw_values;
set raw;
keep A -- E &start. -- &end.;
run;
%macro rename(old,new);
data raw_values;
set raw_values;
rename &old.=&new.;
run;
%mend rename;
data _null_;
set raw_names2;
call execute('%rename('||_name_||","||col1||")");
run;
%macro freq(var);
proc freq data=raw_values noprint;
tables &var. / out=&var.;
run;
%mend freq;
data raw_names3;
set raw_names2;
if _n_ < 6 then delete;
run;
data _null_;
set raw_names3;
call execute('%freq('||col1||")");
run;
proc sort data=raw_values;
by StudySubjectID;
run;
data &lib..&output.;
set raw_values;
run;
%mend raw_sas_datasets;
The problem I'm running into is that the variable names are now all set properly and the data is lined up correctly, but the labels are still the original SAS assigned sequential numbers. Is there any way to set all of the labels equal to the variable names?
If you just want to remove the variable labels (at which point they default to the variable name), that's easy. From the SAS Documentation:
proc datasets lib=&lib.;
modify &output.;
attrib _all_ label=' ';
run;
I suspect you have a simpler solution than the above, though.
The actual renaming step needs to be done differently. Right now it's rewriting the entire dataset over and over again - for a lot of variables that is a terrible idea. Get your rename statements all into one datastep, or into a PROC DATASETS, or something else. Look up 'list processing SAS' for details on how to do that; on this site or on google you will find lots of solutions.
You likely can get SAS to read in the whole first line. The number of variables isn't the problem; it is probably the length of the line. There's another question that I'll find if I can on this site from a few months ago that deals with this exact problem.
My preferred option is not to use PROC IMPORT for CSVs anyway; I would suggest writing a metadata table that stores the variable names and the length/types for the variables, then using that to write import code. A little more work at first, but only has to be done once per study and you guarantee PROC IMPORT isn't making silly decisions for you.
In the library sashelp is a table vcolumn. vcolumn contains all the names of your variables for each library by table. You could write a macro that puts all your variable names into macro variables and then from there set the label.
Here's some code that I put together (not very pretty) but it does what you're looking for:
data test.label_var;
x=1;
y=1;
label x = 'xx';
label y = 'yy';
run;
proc sql noprint;
select count(*) into: cnt
from sashelp.vcolumn
where memname = 'LABEL_VAR';quit;
%let cnt = &cnt;
proc sql noprint;
select name into: name1 - :name&cnt
from sashelp.vcolumn
where memname = 'LABEL_VAR';quit;
%macro test;
%do i = 1 %to &cnt;
proc datasets library=test nolist;
modify label_var;
label &&name&i=&&name&i;
quit;
%end;
%mend test;
%test;

SAS - How to get last 'n' observations from a dataset?

How can you create a SAS data set from another dataset using only the last n observations from original dataset. This is easy when you know the value of n. If I don't know 'n' how can this be done?
This assumes you have a macro variable that says how many observations you want. NOBS tells you the number of observations in the dataset currently without reading the whole thing.
%let obswant=5;
data want;
set sashelp.class nobs=obscount;
if _n_ gt (obscount-&obswant.);
run;
Using Joe's example of a macro variable to specify the number of observations you want, here is another answer:
%let obswant = 10;
data want;
do _i_=nobs-(&obswant-1) to nobs;
set have point=_i_ nobs=nobs;
output;
end;
stop; /* Needed to stop data step */
run;
This should perform better since it only reads the specific observations you want.
If the dataset is large, you might not want to read the whole dataset. Instead you could try a construction that reads the total number of Observations in the dataset first. So if you want to have the last of observations:
data t;
input x;
datalines;
1
2
3
4
;
%let dsid=%sysfunc(open(t));
%let num=%sysfunc(attrn(&dsid,nlobs));
%let rc=%sysfunc(close(&dsid));
%let number = 2;
data tt;
set t (firstobs = %eval(&num.-&number.+1));
run;
For the sake of variety, here's another approach (not necessarily a better one)
%let obswant=5;
proc sql noprint;
select nlobs-&obswant.+1 into :obscalc
from dictionary.tables
where libname='SASHELP' and upcase(memname)='CLASS';
quit;
data want;
set sashelp.class (firstobs=&obscalc.);
run;
You can achive this using the
_nobs_ and _n_ variables. First, create a temporary variable to store the total no of obs. Then compare the automatic variable N to nobs.
data a;
set sashelp.class nobs=_nobs_;
if _N_ gt _nobs_ -5;
run;

Drop a range of variables in SAS

I currently have a dataset with 200 variables. From those variables, I created 100 new variables. Now I would like to drop the original 200 variables. How can I do that?
Slightly better would be, how I can drop variables 3-200 in the new dataset.
sorry if I was vague in my question but basically I figured out I need to use --.
If my first variable is called first and my last variable is called last, I can drop all the variables inbetween with (drop= first--last);
Thanks for all the responses.
As with most SAS tasks, there are several alternatives. The easiest and safest way to drop variables from a SAS data set is with PROC SQL. Just list the variables by name, separated by a comma:
proc sql;
alter table MYSASDATA
drop name, age, address;
quit;
Altering the table with PROC SQL removes the variables from the data set in place.
Another technique is to recreate the data set using a DROP option:
data have;
set have(drop=name age address);
run;
And yet another way is using a DROP statement:
data have;
set have;
drop name age address;
run;
Lots of options - some 'safer', some less safe but easier to code. Let's imagine you have a dataset with variables ID, PLNT, and x1-x200 to start with.
data have;
id=0;
plnt=0;
array x[200];
do _t = 1 to dim(x);
x[_t]=0;
end;
run;
data want;
set have;
*... create new 100 variables ... ;
*option 1:
drop x1-x200; *this works when x1-x200 are numerically consecutive;
*option 2:
drop x1--x200; *this works when they are physically in order on the dataset -
only the first and last matter;
run;
*Or, do it this way. This would also work with SQL ALTER TABLE. This is
the safest way to do it.;
proc sql;
select name into :droplist separated by ' ' from dictionary.columns
where libname='WORK' and memname='HAVE' and name not in ('ID','PRNT');
quit;
proc datasets lib=work;
modify want;
drop &droplist.;
quit;
If all of the variables you want to drop are named so they all start the same (like old_var_1, old_var_2, ..., old_var_n), you could do this (note the colon in drop option):
data have;
set have(drop= old_var:);
run;
data want;
set have;
drop VAR1--VARx;
run;
Would love to know if you can do this by position.
Definitely works with variable names separated by double dash (--).
I have some macros that would allow this here
You could run that whole set of macros, or just run list_vars(), is_blank(), num_words, find_word, remove_word, remove_words , nth_word().
Using these it would be:
%let keep_vars = keep_this and_this also_this;
%let drop_vars = %list_vars(old_dataset);
%let drop_vars = %remove_words(&drop_vars , &keep_vars);
data new_dataset (drop = &drop_vars );
set old_dataset;
/*stuff happens*/
run;
This will keep the three variables keep_this and_this also_this but drop everything else in the old dataset.