SAS: Creating lag variables with a do macro - sas

I'm trying to create 4 new lag variables, each one adding an additional lag. The code below produces only the final lag variable, i.e. after running this code there is a new variable called lag_4, but lag_1, lag_2, and lag_3 are not created. Thanks
%macro makelags;
%do i=1 %to 4;
data work.test1;
set work.dataset;
lag_&i = lag&i(id_number);
run;
%end;
%mend makelags;
%makelags;


You need to loop inside the data step, not outside of it.
If you were to loop:
data work.test1;
set work.dataset;
%do i = 1 %to 4;
lag_&i. = lag&i.(id_number);
%end;
run;
(The whole datastep can be inside a macro, or just the %do loop).
The way I'd do it, if I needed a macro (Because, say, the number of lags varies):
%macro lagme(num_lags=);
%do _i = 1 %to &num_lags.;
lag_&_i. = lag&_i.(id_number);
%end;
%mend lagme;
data mydata;
set olddata;
%lagme(num_lags=4);
run;


Your code is overwriting dataset test1 4 times keeping only the version created by the last %do iteration.
Try moving the %do cycle inside the data step:
data work.test1;
set work.dataset;
%do i=1 %to 4;
lag_&i = lag&i(id_number);
%end;
run;

Related

How can I loop different where statements in the dataset in SAS

I have multiple conditional where statements for the variables such as:
where 1<ColA<3;
where 4<ColB<6;
where 2<ColC<6;
.....
where 5<ColN<8;
I want to subset each of the datasets based on those where statements one by one like:
data newds1;
set original;
where 1<ColA<3;
run;
data newds2;
set original;
where 4<ColB<6;
run;
.....
data newdsn;
set original;
where 5<ColN<8;
run;
How can I do that in a loop in SAS?

Create a macro to do the loop for you. You can pipe-separate all of your where statements and loop through each one.
%macro subset(data=, conditions=, out=);
%let n = %sysfunc(countw(&conditions., |) );
%do i = 1 %to &n.;
%let where = %sysfunc(scan(&conditions., &i., |) );
data &out.&i.;
set &data.;
where &where.;
run;
%end;
%mend;
%subset(data=original, conditions=1<ColA<3 | 4<ColB<6 | 2<ColC<6, out=newds);

Execution of data step despite of the errors

I am executing the following code to combine a large number of data sets . Here is code:
%macro combine;
data modelfit;
set
%do i = 30 %to 116 %by 3 ;
stat&i
%end;
;
%end;
run;
%mend;
%combine;
However, few of the data sets are not present. Hence, the data set is failing to execute. How can I prevent the data step from stopping to execute and combine the data sets that are there . Can anybody please help me with this

Check if the files exist before adding them in the loop:
%macro combine;
data modelfit;
set
%do i = 30 %to 116 %by 3 ;
%if %sysfunc(exist(stat&i)) %then %do ; stat&i %end ;
%end;
;
run;
%mend;
%combine;

Macro to loop through variables and store results SAS

I have the following variables: A_Bldg B_Bldg C_Bldg D_Bldg. I want to multiply them by INTSF and store the result in a new variable, Sale_i. For example, A_Bldg * INTSF = Sale_A, B_Bldg * INTSF = Sale_B, and so on.
My code is:
%macro loopit(mylist);
%let n=%sysfunc(countw(&mylist));
%do J = 1 %to &n;
%let i = %scan(&mylist,&J);
data test;
set data;
sale_&i. = &i._Bldg * INTSF;
run;
%end;
%mend;
%let list = A B C D;
%loopit(&list);
This only produces Sale_D, which is the last letter in the list. How do I get Sales A-C to appear? The first four lines of code are so I can loop through the text A-D. I thought about doing it with arrays, but didn't know how to choose the variables based on the A-D indicators. Thanks for your help!

You're currently looping through your list and recreating the test dataset every time, so it only appears to have sale_d because you're only viewing the last iteration.
You can clean up your loop by scanning through your list in one data step to solve your problem:
%let list = A B C D;
%macro loopit;
data test;
set data;
%do i = 1 %to %sysfunc(countw(&list.));
%let this_letter = %scan(&list., &i.);
sale_&this_letter. = &this_letter._Bldg * INTSF;
%end;
run;
%mend loopit;
%loopit;

Your %DO loop is in the wrong place. But really you do not need to use macro code to do something that the native SAS code can already do.
data want;
set have ;
array in A_Bldg B_Bldg C_Bldg D_Bldg ;
array out sale_1-sale4 ;
do i=1 to dim(in);
out(i)=intsf*in(i);
end;
run;

Find three most recent data year for each row

I have a data set with one row for each country and 100 columns (10 variables with 10 data years each).
For each variable I am trying to make a new data set with the three most recent data years for that variable for each country (which might not be successive).
This is what I have so far, but I know its wrong because of the nest loop, and its has same value for recent1 recent2 recent3 however I haven't figured out how to create recent1 recent2 recent3 without two loops.
%macro test();
data Maternal_care_recent;
set wb;
keep country MATERNAL_CARE_2004 -- MATERNAL_CARE_2013 recent_1 recent_2 recent_3;
%let rc = 1;
%do i = 2013 %to 2004 %by -1;
%do rc = 1 %to 3 %by 1;
%if MATERNAL_CARE_&i. ne . %then %do;
recent_&rc. = MATERNAL_CARE_&i.;
%end;
%end;
%end; run; %mend; %test();

You don't need to use a macro to do this - just some arrays:
data Maternal_care_recent;
set wb;
keep country MATERNAL_CARE_2004-MATERNAL_CARE_2013 recent_1 recent_2 recent_3;
array mc {*} MATERNAL_CARE_2004-MATERNAL_CARE_2013;
array recent {*} recent1-recent3;
do i = 2013 to 2004 by -1;
do rc = 1 to 3 by 1;
if mc[i] ne . then do;
recent[rc] = mc[i];
end;
end;
run;

Maybe I don't get your request, but according to your description:
"For each variable I am trying to make a new data set with the three most recent data years for that variable for each country (which might not be successive)" I created this sample dataset with dt1 and dt2 and 2 locations.
The output will be 2 datasets (and generally the number of the variables starting with DT) named DS1 and DS2 with 3 observations for each country, the first one for the first variable, the second one for the second variable.
This is the sample dataset:
data sample_ds;
length city $10 dt1 dt2 8.;
infile datalines dlm=',';
input city $ dt1 dt2;
datalines;
MS,5,0
MS,3,9
MS,3,9
MS,2,0
MS,1,8
MS,1,7
CA,6,1
CA,6,.
CA,6,.
CA,2,8
CA,1,5
CA,0,4
;
This is the sample macro:
%macro help(ds=);
data vars(keep=dt:); set &ds; if _n_ not >0; run;
%let op = %sysfunc(open(vars));
%let nvrs = %sysfunc(attrn(&op,nvars));
%let cl = %sysfunc(close(&op));
%do idx=1 %to &nvrs.;
proc sort data=&ds(keep=city dt&idx.) out=ds&idx.(where=(dt&idx. ne .)) nodupkey; by city DESCENDING dt&idx.; run;
data ds&idx.; set ds&idx.;
retain cnt;
by city DESCENDING dt&idx.;
if first.city then cnt=0; else cnt=cnt+1;
run;
data ds&idx.(drop=cnt); set ds&idx.(where=(cnt<3)); rename dt&idx.=act&idx.; run;
%end;
%mend;
You will run this macro with:
%help(ds=sample_ds);
In the first statement of the macro I select the variables on which I want to iterate:
data vars(keep=dt:); set &ds; if _n_ not >0; run;
Work on this if you want to make this work for your code, or simply rename your variables as DT1 DT2...
Let me know if it is correct for you.

When writing macro code, always keep in mind what has to be done when. SAS processes your code stepwise.
Before your sas code is even compiled, your macro variables are resolved and your macro code is executed
Then the resulting SAS Base code is compiled
Finally the code is executed.
When you write %if MATERNAL_CARE_&i. ne . %then %do, this is macro code interpreded before compilation.
At that time MATERNAL_CARE_&i. is not a variable but a text string containing a macro variable.
The first time you run trhough your %do i = 2013 %to 2004 by -1, it is filled in as MATERNAL_CARE_2013, the second as MATERNAL_CARE_2012., etc.
Then the macro %if statement is interpreted, and as the text string MATERNAL_CARE_1 is not equal to a dot, it is evaluated to FALSE
and recent_&rc. = MATERNAL_CARE_&i. is not included in the code to pass to your compiler.
You can see that if you run your code with option mprint;
The resolution;
options mprint;
%macro test();
data Maternal_care_recent;
set wb;
keep country MATERNAL_CARE_: recent_:;
** The : acts as a wild card here **;
%do i = 2013 %to 2004 %by -1;
if MATERNAL_CARE_&i. ne . then do;
%do rc = 1 %to 3 %by 1;
recent_&rc. = MATERNAL_CARE_&i.;
%end;
end;
%end;
run;
%mend;
%test();
Now, before compilation of if MATERNAL_CARE_&i. ne . then do, only the &i. is evalueated and if MATERNAL_CARE_2013 ne . then do is passed to the compiler.
The compiler will see this as a test if the SAS variable MATERNAL_CARE_1 has value missing, and that is just what you wanted;
Remark:
It is not essential that I moved the if statement above the ``. It is just more efficient because the condition is then evaluated less often.
It is however essential that you close your %ifs and %dos with an %end and your ifs and dos with an end;
Remark:
you do not need %let rc = 1, because %do rc = 1 to 3 already initialises &rc.;
For completeness SAS is compiled stepwise:
The next PROC or data step and its macro code are only considered when the preveous one is executed.
That is why you can write macro variables from a data step or sql select into that will influence the code you compile in your next step,
somehting you can not do for instance with C++ pre compilation;

Thanks everyone. Found a hybrid solution from a few solutions posted.
data sample_ds;
infile datalines dlm=',';
input country $ maternal_2004 maternal_2005
maternal_2006 maternal_2007 maternal_2008 maternal_2009 maternal_2010 maternal_2011 maternal_2012 maternal_2013;
datalines;
MS,5,0,5,0,5,.,5,.,5,.
MW,3,9,5,0,5,0,5,.,5,0
WE,3,9,5,0,5,.,.,.,.,0
HU,2,0,5,.,5,.,5,0,5,0
MI,1,8,5,0,5,0,5,.,5,0
HJ,1,7,5,0,5,0,.,0,.,0
CJ,6,1,5,0,5,0,5,0,5,0
CN,6,1,.,5,0,5,0,5,0,5
CE,6,5,0,5,0,.,0,5,.,8
CT,2,5,0,5,0,5,0,5,0,9
CW,1,5,0,5,0,5,.,.,0,7
CH,0,5,0,5,0,.,0,.,0,5
;
%macro test(var);
data &var._recent;
set sample_ds;
keep country &var._1 &var._2 &var._3;
array mc {*} &var._2004-&var._2013;
array recent {*} &var._1-&var._25;
count=1;
do i = 10 to 1 by -1;
if mc[i] ne . then do;
recent[count] = mc[i];
count=count+1;
end;
end;
run;
%mend;

SAS Is it possible not to use "TO" in a do loop in MACRO?

I used to use a %do ... %to and it worked fine , but I when I tried to list all character values without %to I got a message ERROR: Expected %TO not found in %DO statement
%macro printDB2 ;
%let thisName = ;
%do &thisName = 'Test1' , 'Test2' , 'Test3' ;
proc print data=&thisName ;
run ;
%end ;
%mend printDB2 ;
I know how to complete this task using %to or %while . But I am curious is it possible to list all character values in the %do ? How can I %do this ?

If your goal here is to loop through a series of character values in some macro logic, one approach you could take is to define corresponding sequentially named macro variables and loop through those, e.g.
%let mvar1 = A;
%let mvar2 = B;
%let mvar3 = C;
%macro example;
%do i = 1 %to 3;
%put mvar&i = &&mvar&i;
%end;
%mend example;
%example;
Alternatively, you could scan a list of values repeatedly and redefine the same macro var multiple times within your loop:
%let list_of_values = A B C;
%macro example2;
%do i = 1 %to 3;
%let mvar = %scan(&list_of_values, &i, %str( ));
%put mvar = &mvar;
%end;
%mend example2;
%example2;
I've explicitly specified that I want to use space as the only list delimiter for scan - otherwise SAS uses lots default delimiters.