Creating Combinations in SAS - sas

Helloo..So am trying to derive combinations of 3 variables from 378 variables on SAS. Any help?
I have tried the below code but no luck:
Proc plan;
Factors Block=8930376 ordered
Variable=2 of 378 comb;
Ods output Plan=Comb_MEV;
Quit;

This is a modified version of the example for ALLCOMBI
data comb;
array i[3];
n=378;
k=3;
i[1]=0;
ncomb=comb(n,k); /* The one extra call goes back */
do j=1 to ncomb+1; /* to the first combination. */
call allcombi(n, k, of i[*]);
output;
end;
run;
proc print data=comb(obs=40);
run;

Related

SaS 9.4: How to use different weights on the same variable without datastep or proc sql

I can't find a way to summarize the same variable using different weights.
I try to explain it with an example (of 3 records):
data pippo;
a=10;
wgt1=0.5;
wgt2=1;
wgt3=0;
output;
a=3;
wgt1=0;
wgt2=0;
wgt3=1;
output;
a=8.9;
wgt1=1.2;
wgt2=0.3;
wgt3=0.1;
output;
run;
I tried the following:
proc summary data=pippo missing nway;
var a /weight=wgt1;
var a /weight=wgt2;
var a /weight=wgt3;
output out=pluto (drop=_freq_ _type_) sum()=;
run;
Obviously it gives me a warning because I used the same variable "a" (I can't rename it!).
I've to save a huge amount of data and not so much physical space and I should construct like 120 field (a0-a6,b0-b6 etc) that are the same variables just with fixed weight (wgt0-wgt5).
I want to store a dataset with 20 columns (a,b,c..) and 6 weight (wgt0-wgt5) and, on demand, processing a "summary" without an intermediate datastep that oblige me to create 120 fields.
Due to the huge amount of data (more or less 55Gb every month) I'd like also not to use proc sql statement:
proc sql;
create table pluto
as select sum(db.a * wgt1) as a0, sum(db.a * wgt1) as a1 , etc.
quit;
There is a "Super proc summary" that can summarize the same field with different weights?
Thanks in advance,
Paolo
I think there are a few options. One is the data step view that data_null_ mentions. Another is just running the proc summary however many times you have weights, and either using ods output with the persist=proc or 20 output datasets and then setting them together.
A third option, though, is to roll your own summarization. This is advantageous in that it only sees the data once - so it's faster. It's disadvantageous in that there's a bit of work involved and it's more complicated.
Here's an example of doing this with sashelp.baseball. In your actual case you'll want to use code to generate the array reference for the variables, and possibly for the weights, if they're not easily creatable using a variable list or similar. This assumes you have no CLASS variable, but it's easy to add that into the key if you do have a single (set of) class variable(s) that you want NWAY combinations of only.
data test;
set sashelp.baseball;
array w[5];
do _i = 1 to dim(w);
w[_i] = rand('Uniform')*100+50;
end;
output;
run;
data want;
set test end=eof;
i = .;
length varname $32;
sumval = 0 ;
sum=0;
if _n_ eq 1 then do;
declare hash h_summary(suminc:'sumval',keysum:'sum',ordered:'a');;
h_summary.defineKey('i','varname'); *also would use any CLASS variable in the key;
h_summary.defineData('i','varname'); *also would include any CLASS variable in the key;
h_summary.defineDone();
end;
array w[5]; *if weights are not named in easy fashion like this generate this with code;
array vars[*] nHits nHome nRuns; *generate this with code for the real dataset;
do i = 1 to dim(w);
do j = 1 to dim(vars);
varname = vname(vars[j]);
sumval = vars[j]*w[i];
rc = h_summary.ref();
if i=1 then put varname= sumval= vars[j]= w[i]=;
end;
end;
if eof then do;
rc = h_summary.output(dataset:'summary_output');
end;
run;
One other thing to mention though... if you're doing this because you're doing something like jackknife variance estimation or that sort of thing, or anything that uses replicate weights, consider using PROC SURVEYMEANS which can handle replicate weights for you.
You can SCORE your data set using a customized SCORE data set that you can generate
with a data step.
options center=0;
data pippo;
retain a 10 b 1.75 c 5 d 3 e 32;
run;
data score;
if 0 then set pippo;
array v[*] _numeric_;
retain _TYPE_ 'SCORE';
length _name_ $32;
array wt[3] _temporary_ (.5 1 .333);
do i = 1 to dim(v);
call missing(of v[*]);
do j = 1 to dim(wt);
_name_ = catx('_',vname(v[i]),'WGT',j);
v[i] = wt[j];
output;
end;
end;
drop i j;
run;
proc print;[enter image description here][1]
run;
proc score data=pippo score=score;
id a--e;
var a--e;
run;
proc print;
run;
proc means stackods sum;
ods exclude summary;
ods output summary=summary;
run;
proc print;
run;
enter image description here

SAS - creating indicator variables

I'm using SAS and I'd like to create an indicator variable.
The data I have is like this (DATA I HAVE):
and I want to change this to (DATA I WANT):
I have a fixed number of total time that I want to use, and the starttime has duplicate time value (in this example, c1 and c2 both started at time 3). Although the example I'm using is small with 5 names and 12 time values, the actual data is very large (about 40,000 names and 100,000 time values - so the outcome I want is a matrix with 100,000x40,000.)
Can someone please provide any tips/solution on how to handle this?
40k variables is a lot. It will be interesting to see how well this scales. How do you determine the stop time?
data have;
input starttime name :$32.;
retain one 1;
cards;
1 varx
3 c1
3 c2
5 c3x
10 c4
11 c5
;;;;
run;
proc print;
run;
proc transpose data=have out=have2(drop=_name_ rename=(starttime=time));
by starttime;
id name;
var one;
run;
data time;
if 0 then set have2(drop=time);
array _n[*] _all_;
retain _n 0;
do time=.,1 to 12;
output;
call missing(of _n[*]);
end;
run;
data want0 / view=want0;
merge time have2;
by time;
retain dummy '1';
run;
data want;
length time 8;
update want0(obs=0) want0;
by dummy;
if not missing(time);
output;
drop dummy;
run;
proc print;
run;
This will work. There may be a simpler solution that does it all in one data step. My data step creates a staggered results that has to be collapsed which I do by summing in the sort/means.
data have;
input starttime name $;
datalines;
3 c1
3 c2
5 c3
10 c4
11 c5
;
run;
data want(drop=starttime name);
set have;
array cols (*) c1-c5;
do time=1 to 100;
if starttime < time then cols(_N_)=1;
else cols(_N_)=0;
output;
end;
run;
proc sort data=want;
by time;
proc means data=want noprint;
by time;
var _numeric_;
output out=want2(drop=_type_ _freq_) sum=;
run;
I am not recommending you do it this way. You didn't provide enough information to let us know why you want a matrix of that size. You may have processing issues getting it to run.
In the line do time=1 to 100 you can change that to 100000 or whatever length.
I think the code below will work:
%macro answer_macro(data_in, data_out);
/* Deduplication of initial dataset just to assure that every variable has a unique starting time*/
proc sort data=&data_in. out=data_have_nodup; by name starttime; run;
proc sort data=data_have_nodup nodupkey; by name; run;
/*Getting min and max starttime values - here I am assuming that there is only integer values form starttime*/
proc sql noprint;
select min(starttime)
,max(starttime)
into :min_starttime /*not used. Use this (and change the loop on the next dataset) to start the time variable from the value where the first variable starts*/
,:max_starttime
from data_have_nodup
;quit;
/*Getting all pairs of name/starttime*/
proc sql noprint;
select name
,starttime
into :name1 - :name1000000
,:time1 - :time1000000
from data_have_nodup
;quit;
/*Getting total number of variables*/
proc sql noprint;
select count(*) into :nvars
from data_have_nodup
;quit;
/* Creating dataset with possible start values */
/*I'm not sure this step could be done with a single datastep, but I don't have SAS
on my PC to make tests, so I used the method below*/
data &data_out.;
do i = 1 to &max_starttime. + 1;
time = i; output;
end;
drop i;
run;
data &data_out.;
set &data_out.;
%do i = 1 %to &nvars.;
if time >= &&time&i then &&name&i = 1;
else &&name&i = 0;
%end;
run;
%mend answer_macro;
Unfortunately I don't have SAS on my machine right now, so I can't confirm that the code works. But even if it doesn't, you can use the logic in it.

Where is the missing operator in the SAS MIN function?

I'm just starting out in SAS and have run into some troubles. I want to get the number of observations from two data sets and assign those values to existing global macro variables. Then I want to find the smaller of the two. This is my attempt so far:
%GLOBAL nBlue = 0;
%GLOBAL nRed = 0;
%MACRO GetArmySizes(redData=, blueData=);
/* Takes in 2 Army Datasets, and outputs their respective sizes to nBlue and nRed */
data _Null_;
set &blueData nobs=j;
if _N_ =2 then stop;
No_of_obs=j;
call symput("nBlue",j);
run;
data _Null_;
set &redData nobs=j;
if _N_ =2 then stop;
No_of_obs=j;
call symput("nRed",j);
run;
%put &nBlue;
%put &nRed;
%MEND;
%put &nBlue; /* outputs 70 here */
%put &nRed; /* outputs 100 here */
%put %EVAL(min(1,5));
%GetArmySizes(redData=redTeam1, blueData=blueTeam); /* outputs 70\n100 here */
%put &nBlue; /* outputs 70 here */
%put &nRed; /* outputs 100 here */
%MACRO PrepareOneVOneArmies(redData=,numRed=,blueData=,numBlue=);
/* Takes in two army data sets and their sizes, and outputs two new army
data sets with the same number of observations */
%let smallArmy = %eval(min(&numRed,&numBlue));
%put &smallArmy;
%local numOneVOne;
%let numOneVOne = %eval(&smallArmy-%Eval(&nBlue - &nRed));
%put &numOneVOne;
data redOneVOne; set &redData (obs=&numOneVOne);
run;
data blueOneVOne; set &blueData (obs=&numOneVOne);
run;
%MEND;
%PrepareOneVOneArmies(redData=redTeam1,numRed=&nRed,blueData=blueTeam,numBlue=&nBlue);
/* stops executing when program gets to %let smallArmy =... */
redTeam1 is a data set with 100 observations, blueTeam has 70 observations.
I now run into the problem where whenever I call the function "Min" I get:
"ERROR: Required operator not found in expression: min(1,5)"
or
"ERROR: Required operator not found in expression: min(100,70)"
What am I missing?
"Min" seems like a simple enough function. Also, if it matters, I am using the University edition of SAS.
While using functions in macro language you need to wrap the function in %SYSFUNC(). This helps sas delineate from a word that could be min versus a reference to an actual function.
%put %sysfunc(min(1,5));
Not related to your question, but for obtaining the size of a dataset, reading the full data set is an inefficient method. Consider using the dictionary table (SASHELP.VTABLE) instead.

Infinite Loop while using Do while in SAS

I am very new but keen to learn SAS coding.I have 2 data sets a and b namely dt1 and dt2 which consist of columns a for dt1 and b and c for dt2:
a b c
2014 2008 2
2009 3
2014 4
2015 5
I am trying to get the nth row of the c column when the element which is at nth row of b column is equal to a(1)
Here it is c=4;
I wrote a code below.
DATA dt1;
set dt1;
data dt2;
set dt2;
i=1;
do while (b ne a);
i=i+1;
end;
call symput('ROW_NUMBER',i);
run;
proc print data = dt2(keep = c obs = &ROW_NUMBER firstobs = &ROW_NUMBER);
run;
but this code enters in an infinite loop and I could not find any solution for this. I appreciate if you help solve this issue.
Thanks
I think you should learn the basic syntax of the data step before trying to use macro variables. A lot of what you're doing makes little sense. Here is an explanation of how the data step works. You will do yourself a huge favor if you study that.
Here's how to do an inner join in proc sql, which seems to be more in line with your goal here. This simply selects the values of c where dt1.a is equal to dt2.b:
proc sql;
select c
from dt1 inner join dt2 on dt1.a = dt2.b;
quit;
If you were to use a data step, you'd do something like this the following.
data out(keep=c);
set dt1;
do until (a=b or eof);
set dt2 end=eof;
if a=b then output;
end;
run;
proc print data=out noobs;
run;
Use the end= option to create temporary variable eof which allows you to end the loop after the last row of dt2 is read.
This is a simple MERGE. You just need to rename the variables to match. This assumes they're both sorted by the value (a/b). You can then set the macro variable in that data step or do whatever you want.
data want;
merge dt1(in=_a rename=a=b) dt2(in=_b);
by b;
if _a and _b;
call symput("ROW_NUMBER",c);
run;
If you want to define macro variables:
data _null_;
set dt2;
if _n_=1 then set dt1;
if a=b then do;
call symput('c_val',c);
call symput('row_num',_n_);
end;
run;
%put &row_num &c_val;

Macro returning a value

I created the following macro. Proc power returns table pw_cout containing column Power. The data _null_ step assigns the value in column Power of pw_out to macro variable tpw. I want the macro to return the value of tpw, so that in the main program, I can call it in DATA step like:
data test;
set tmp;
pw_tmp=ttest_power(meanA=a, stdA=s1, nA=n1, meanB=a2, stdB=s2, nB=n2);
run;
Here is the code of the macro:
%macro ttest_power(meanA=, stdA=, nA=, meanB=, stdB=, nB=);
proc power;
twosamplemeans test=diff_satt
groupmeans = &meanA | &meanB
groupstddevs = &stdA | &stdB
groupns = (&nA &nB)
power = .;
ods output Output=pw_out;
run;
data _null_;
set pw_out;
call symput('tpw'=&power);
run;
&tpw
%mend ttest_power;
#itzy is correct in pointing out why your approach won't work. But there is a solution maintaing the spirit of your approach: you need to create a power-calculation function uisng PROC FCMP. In fact, AFAIK, to call a procedure from within a function in PROC FCMP, you need to wrap the call in a macro, so you are almost there.
Here is your macro - slightly modified (mostly to fix the symput statement):
%macro ttest_power;
proc power;
twosamplemeans test=diff_satt
groupmeans = &meanA | &meanB
groupstddevs = &stdA | &stdB
groupns = (&nA &nB)
power = .;
ods output Output=pw_out;
run;
data _null_;
set pw_out;
call symput('tpw', power);
run;
%mend ttest_power;
Now we create a function that will call it:
proc fcmp outlib=work.funcs.test;
function ttest_power_fun(meanA, stdA, nA, meanB, stdB, nB);
rc = run_macro('ttest_power', meanA, stdA, nA, meanB, stdB, nB, tpw);
if rc = 0 then return(tpw);
else return(.);
endsub;
run;
And finally, we can try using this function in a data step:
options cmplib=work.funcs;
data test;
input a s1 n1 a2 s2 n2;
pw_tmp=ttest_power_fun(a, s1, n1, a2, s2, n2);
cards;
0 1 10 0 1 10
0 1 10 1 1 10
;
run;
proc print data=test;
You can't do what you're trying to do this way. Macros in SAS are a little different than in a typical programming language: they aren't subroutines that you can call, but rather just code that generate other SAS code that gets executed. Since you can't run proc power inside of a data step, you can't run this macro from a data step either. (Just imagine copying all the code inside the macro into the data step -- it wouldn't work. That's what a macro in SAS does.)
One way to do what you want would be to read each observation from tmp one at a time, and then run proc power. I would do something like this:
/* First count the observations */
data _null_;
call symputx('nobs',obs);
stop;
set tmp nobs=obs;
run;
/* Now read them one at a time in a macro and call proc power */
%macro power;
%do j=1 %to &nobs;
data _null_;
nrec = &j;
set tmp point=nrec;
call symputx('meanA',meanA);
call symputx('stdA',stdA);
call symputx('nA',nA);
call symputx('meanB',meanB);
call symputx('stdB',stdB);
call symputx('nB',nB);
stop;
run;
proc power;
twosamplemeans test=diff_satt
groupmeans = &meanA | &meanB
groupstddevs = &stdA | &stdB
groupns = (&nA &nB)
power = .;
ods output Output=pw_out;
run;
proc append base=pw_out_all data=pw_out; run;
%end;
%mend;
%power;
By using proc append you can store the results of each round of output.
I haven't checked this code so it might have a bug, but this approach will work.
You can invoke a macro which calls procedures, etc. (like the example) from within a datastep using call execute(), but it can get a bit messy and difficult to debug.