SAS transpose when data are missing - sas

I have a data set with a large number of lab tests done at different points in time. I am trying to transpose the data set from long to wide, but the problem is that the lab tests occur at different time points depending upon the type of test. When I transpose it, I'm losing my ability to tell which time point the result is from. See my example code below:
*Create test data;
data long;
do subject=1 to 10;
do test=1 to 3;
do visit=1 to 3;
result=rand("Uniform");
output;
end; end; end;
run;
*Now remove records at certain visits depending upon the test type;
data long; set long;
if test=2 and visit=2 then delete;
if test=3 and visit=1 then delete;
run;
*Sort and transpose;
*Test 2 should only be at visit 1 and 3, and test 3 at visits 2 and 3;
*This transpose does not accomplish that goal;
proc sort data=long; by subject test visit;run;
proc transpose data=long out=wide;
by subject test ;
var result;
run;

For your example data you just need to add an ID statement to your PROC TRANSPOSE code. That way it will use value of VISIT to name the resulting columns. You might also want to add the PREFIX= option to the PROC TRANSPOSE statement.
proc transpose data=long out=wide prefix=visit;
by subject test ;
id visit ;
var result;
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

Combing/Collapsing binary variables into a single row by patient ID in SAS

I am trying to collapse my multiple rows of binary variables into a single row per patient id as depicted in my illustration. Could someone please help me with the SAS code to do this? Thanks
If the rule is that to set it to 1 if it is ever 1 then take the MAX. If the rule is to set it to one only if all of them are one then take the MIN.
proc summary data=have nway ;
by id;
output out=want max= ;
run;
Update trick
data want;
update have(obs=0) have;
by id;
run;
Or
proc sql;
create table want as
select ID, max('2018'n) as Y2018, max('2019'n) as Y2019, max('2020'n) as Y2020
from have
group by ID
order by ID;
quit;
Untested because you provided data as images, please post as text, preferably as a data step.
Here is a data step-based solution. Certainly more complex than the above answers, but it does show ways you can use arrays, first. and last. processing, and the retain statement.
Use a retained temporary array to hold the values of 2018-2020 until the last observation of each id group. On the last value of each id, check if each held value is 1 and set each value of the year to a 1 or 0.
data want;
set have;
by id;
array year[3] '2018'n--'2020'n;
array hold[3] _TEMPORARY_;
retain hold;
if(first.id) then call missing(of hold[*]);
do i = 1 to dim(year);
if(year[i] = 1) then hold[i] = 1;
end;
if(last.id) then do;
do i = 1 to dim(year);
year[i] = (hold[i] = 1);
end;
output;
end;
drop i;
run;

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.

How do I create a SAS data view from an 'Out=' option?

I have a process flow in SAS Enterprise Guide which is comprised mainly of Data views rather than tables, for the sake of storage in the work library.
The problem is that I need to calculate percentiles (using proc univariate) from one of the data views and left join this to the final table (shown in the screenshot of my process flow).
Is there any way that I can specify the outfile in the univariate procedure as being a data view, so that the procedure doesn't calculate everything prior to it in the flow? When the percentiles are left joined to the final table, the flow is calculated again so I'm effectively doubling my processing time.
Please find the code for the univariate procedure below
proc univariate data=WORK.QUERY_FOR_SGFIX noprint;
var CSA_Price;
by product_id;
output out= work.CSA_Percentiles_Prod
pctlpre= P
pctlpts= 40 to 60 by 10;
run;
In SAS, my understanding is that procs such as proc univariate cannot generally produce views as output. The only workaround I can think of would be for you to replicate the proc logic within a data step and produce a view from the data step. You could do this e.g. by transposing your variables into temporary arrays and using the pctl function.
Here's a simple example:
data example /view = example;
array _height[19]; /*Number of rows in sashelp.class dataset*/
/*Populate array*/
do _n_ = 1 by 1 until(eof);
set sashelp.class end = eof;
_height[_n_] = height;
end;
/*Calculate quantiles*/
array quantiles[3] q40 q50 q60;
array points[3] (40 50 60);
do i = 1 to 3;
quantiles[i] = pctl(points[i], of _height{*});
end;
/*Keep only the quantiles we calculated*/
keep q40--q60;
run;
With a bit more work, you could also make this approach return percentiles for individual by groups rather than for the whole dataset at once. You would need to write a double-DOW loop to do this, e.g.:
data example;
array _height[19];
array quantiles[3] q40 q50 q60;
array points[3] _temporary_ (40 50 60);
/*Clear heights array between by groups*/
call missing(of _height[*]);
/*Populate heights array*/
do _n_ = 1 by 1 until(last.sex);
set class end = eof;
by sex;
_height[_n_] = height;
end;
/*Calculate quantiles*/
do i = 1 to 3;
quantiles[i] = pctl(points[i], of _height{*});
end;
/* Output all rows from input dataset, with by-group quantiles attached*/
do _n_ = 1 to _n_;
set class;
output;
end;
keep name sex q40--q60;
run;

Using proc freq with repeated ID variables

I would like to use proq freq to count the number of food types that someone consumed on a specific day(fint variable). My data is in long format with repeated idno for the different food types and different number of interview dates. However SAS hangs and does not run the code. I have more than 300,000 datalines.Is there another way to do this?
proc freq;
tables idno*fint*foodtype / out=countft;
run;
I am a little unsure of your data structure, but proc means can also count.
Assuming that you have multiple dates for each person, and multiple food types for each date, you can use:
data dataset;
set dataset;
count=1;
run;
proc means data=dataset sum;
class idno fint foodtype;
var count;
output out=countft sum=counftpday;
run;
/* Usually you only want the lines with the largest _type_, so keep going here */
proc sql noprint;
select max(_type_) into :want from countft;
quit; /*This grabs the max _type_ from output file */
data countft;
set countft;
where _type_=&want.;
run;
Try a proc sql:
proc sql;
create table want as
select distinct idno, fint, foodtype, count(*) as count
from have
order by 1, 2, 3;
quit;
Worse case scenario, sort and count in a data step.
proc sort data=have;
by idno fint foodtype;
run;
data count;
set have;
by idno fint foodtype;
if first.foodtype then count=1;
else count+1;
if last.foodtype then output;
run;