Is there an equivalent of R's function predict(model, data) in SAS?
For example, how would you apply the model below to a large test data set where the response variable "Age" is unknown?
proc reg data=sashelp.class;
model Age = Height Weight ;
run;
I understand you can extract the formula Age = Intercept + Height(Estimate_height) + Weight(Estimate_weight) from the results window and manually predict "Age" for unknown observations, but that's not very efficient.
SAS does this by itself. As long as the model has enough data points to go on, it will output the predicted value. I've used proc glm, but you can use any model procedure to create this kind of output.
/* this is a sample dataset */
data mydata;
input age weight dataset $;
cards;
1 10 mydata
2 11 mydata
3 12 mydata
4 15 mydata
5 12 mydata
;
run;
/* this is a test dataset. It needs to have all of the variables that you'll use in the model */
data test;
input weight dataset $;
cards;
6 test
7 test
10 test
;
run;
/* append (add to the bottom) the test to the original dataset */
proc append data=test base=mydata force; run;
/* you can look at mydata to see if that worked, the dependent var (age) should be '.' */
/* do the model */
proc glm data=mydata;
model age = weight/p clparm; /* these options after the '/' are to show predicte values in results screen - you don't need it */
output out=preddata predicted=pred lcl=lower ucl=upper; /* this line creates a dataset with the predicted value for all observations */
run;
quit;
/* look at the dataset (preddata) for the predicted values */
proc print data=preddata;
where dataset='test';
run;
Related
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
I would like to turn the following long dataset:
data test;
input Id Injury $;
datalines;
1 Ankle
1 Shoulder
2 Ankle
2 Head
3 Head
3 Shoulder
;
run;
Into a wide dataset that looks like this:
ID Ankle Shoulder Head
1 1 1 0
2 1 0 1
3 0 1 1'
This answer seemed the most relevant but was falling over at the proc freq stage (my real dataset is around 1 million records, and has around 30 injury types):
Creating dummy variables from multiple strings in the same row
Additional help: https://communities.sas.com/t5/SAS-Statistical-Procedures/Possible-to-create-dummy-variables-with-proc-transpose/td-p/235140
Thanks for the help!
Here's a basic method that should work easily, even with several million records.
First you sort the data, then add in a count to create the 1 variable. Next you use PROC TRANSPOSE to flip the data from long to wide. Then fill in the missing values with a 0. This is a fully dynamic method, it doesn't matter how many different Injury types you have or how many records per person. There are other methods that are probably shorter code, but I think this is simple and easy to understand and modify if required.
data test;
input Id Injury $;
datalines;
1 Ankle
1 Shoulder
2 Ankle
2 Head
3 Head
3 Shoulder
;
run;
proc sort data=test;
by id injury;
run;
data test2;
set test;
count=1;
run;
proc transpose data=test2 out=want prefix=Injury_;
by id;
var count;
id injury;
idlabel injury;
run;
data want;
set want;
array inj(*) injury_:;
do i=1 to dim(inj);
if inj(i)=. then inj(i) = 0;
end;
drop _name_ i;
run;
Here's a solution involving only two steps... Just make sure your data is sorted by id first (the injury column doesn't need to be sorted).
First, create a macro variable containing the list of injuries
proc sql noprint;
select distinct injury
into :injuries separated by " "
from have
order by injury;
quit;
Then, let RETAIN do the magic -- no transposition needed!
data want(drop=i injury);
set have;
by id;
format &injuries 1.;
retain &injuries;
array injuries(*) &injuries;
if first.id then do i = 1 to dim(injuries);
injuries(i) = 0;
end;
do i = 1 to dim(injuries);
if injury = scan("&injuries",i) then injuries(i) = 1;
end;
if last.id then output;
run;
EDIT
Following OP's question in the comments, here's how we could use codes and labels for injuries. It could be done directly in the last data step with a label statement, but to minimize hard-coding, I'll assume the labels are entered into a sas dataset.
1 - Define Labels:
data myLabels;
infile datalines dlm="|" truncover;
informat injury $12. labl $24.;
input injury labl;
datalines;
S460|Acute meniscal tear, medial
S520|Head trauma
;
2 - Add a new query to the existing proc sql step to prepare the label assignment.
proc sql noprint;
/* Existing query */
select distinct injury
into :injuries separated by " "
from have
order by injury;
/* New query */
select catx("=",injury,quote(trim(labl)))
into :labls separated by " "
from myLabels;
quit;
3 - Then, at the end of the data want step, just add a label statement.
data want(drop=i injury);
set have;
by id;
/* ...same as before... */
* Add labels;
label &labls;
run;
And that should do it!
I'm not very familiar with Do Loops in SAS and was hoping to get some help. I have data that looks like this:
Product A: 1
Product A: 2
Product A: 4
I'd like to transpose (easy) and flag that Product A: 3 is missing, but I need to do this iteratively to the i-th degree since the number of products is large.
If I run the transpose part in SAS, my first column will be 1, second column will be 2, and third column will be 4 - but I'd really like the third column to be missing and the fourth column to be 4.
Any thoughts? Thanks.
Get some sample data:
proc sort data=sashelp.iris out=sorted;
by species;
run;
Determine the largest column we will need to transpose to. Depending on your situation you may just want to hardcode this value using a %let max=somevalue; statement:
proc sql noprint;
select cats(max(sepallength)) into :max from sorted;
quit;
%put &=max;
Transpose the data using a data step:
data want;
set sorted;
by species;
retain _1-_&max;
array a[1:&max] _1-_&max;
if first.species then do;
do cnt = lbound(a) to hbound(a);
a[cnt] = .;
end;
end;
a[sepallength] = sepallength;
if last.species then do;
output;
end;
keep species _1-_&max;
run;
Notice we are defining an array of columns: _1,_2,_3,..._max. This happens in our array statement.
We then use by-group processing to populate these newly created columns for a single species at a time. For each species, on the first record, we clear the array. For each record of the species, we populate the appropriate element of the array. On the final record for the species output the array contents.
You need a way to tell SAS that you have 4 products and the values are 1-4. In this example I create dummy ID with the needed information then transpose using ID statement to name new variables using the value of product.
data product;
input id product ##;
cards;
1 1 1 2 1 4
2 2 2 3
;;;;
run;
proc print;
run;
data productspace;
if 0 then set product;
do product = 1 to 4;
output;
end;
stop;
run;
data productV / view=productV;
set productspace product;
run;
proc transpose data=productV out=wide(where=(not missing(id))) prefix=P;
by id;
var product;
id product;
run;
proc print;
run;
In the data for 10000 item_ids, the item description is given so how to count the frequency of individual word in the item description column, for a particular item_id, where the item_id are repeating, using SAS (without using array).
Goal is to identify the keywords for a particular item_id.
Following approach leverage Proc Freq to get 'keyword' distribution.
data have;
infile cards truncover;
input id var $ 100.;
cards;
1 This is test test
2 failed
1 be test
2 failed is
3 success
3 success ok
;
/*This is to break down the description into single word*/
data want;
set have;
do _n_=1 to countw(var);
new_var=scan(var,_n_);
output;
end;
run;
/*This is to give you words freq by id*/
ods output list=mylist (keep=id new_var frequency);
PROC FREQ DATA = want
ORDER=FREQ
;
TABLES id * new_var /
NOCOL
NOPERCENT
NOCUM
SCORES=TABLE
LIST
ALPHA=0.05;
RUN; QUIT;
ods _all_ close;
ods listing;
Arrays are used to read across multiple columns, so aren't of any particular use here. This does sound a bit like a homework question and you should really show some attempt that you've made. However, this is not an easy problem to solve, so I will post a solution.
My thoughts on how to approach this are :
Sort the data by item_id
For every item_id, scan through each word and check if it already exists for that item_id. If so then go to the next word, otherwise add the word to the unique list and increment the counter by 1
When the last of the current item_id's is processed, output the unique word list and count
I've hopefully commented the code below sufficiently for you to follow what's going on, if not then look up the particular function or statement online.
/* create dummy dataset */
data have;
input item_id item_desc $30.;
datalines;
1 this is one
1 this is two
2 how many words are here
2 not many
3 random selection
;
run;
/* sort dataset if necessary */
proc sort data=have;
by item_id;
run;
/* extract unique words from description */
data want;
set have;
by item_id;
retain unique_words unique_count; /* retain value from previous row */
length unique_words $200; /* set length for unique word list */
if first.item_id then do; /* reset unique word list and count when item_id changes */
call missing(unique_words);
unique_count = 0;
end;
do i = 1 by 1 while(scan(item_desc,i) ne ''); /* scan each word in description until the end */
if indexw(unique_words,scan(item_desc,i),'|') > 0 then continue; /* check if word already exists in unique list, if so then go to next word */
else do;
call catx('|',unique_words,scan(item_desc,i)); /* add to list of unique words, separated by | */
unique_count+1; /* count number of unique words */
end;
end;
drop item_desc i; /* drop unwanted columns */
if last.item_id then output; /* output id, unique word list and count when last id */
run;
County...AgeGrp...Population
A.............1..........200
A.............2..........100
A.............3..........100
A............All.........400
B.............1..........200
So, I have a list of counties and I'd like to find the under 18 population as a percent of the population for each county, so as an example from the table above I'd like to add only the population of agegrp 1 and 2 and divide by the 'all' population. In this case it would be 300/400. I'm wondering if this can be done for every county.
Let's call your SAS data set "HAVE" and say it has two character variables (County and AgeGrp) and one numeric variable (Population). And let's say you always have one observation in your data set for a each County with AgeGrp='All' on which the value of Population is the total for the county.
To be safe, let's sort the data set by County and process it in another data step to, creating a new data set named "WANT" with new variables for the county population (TOT_POP), the sum of the two Age Group values you want (TOT_GRP) and calculate the proportion (AgeGrpPct):
proc sort data=HAVE;
by County;
run;
data WANT;
retain TOT_POP TOT_GRP 0;
set HAVE;
by County;
if first.County then do;
TOT_POP = 0;
TOT_GRP = 0;
end;
if AgeGrp in ('1','2') then TOT_GRP + Population;
else if AgeGrp = 'All' then TOT_POP = Population;
if last.County;
AgeGrpPct = TOT_GRP / TOT_POP;
keep County TOT_POP TOT_GRP AgeGrpPct;
output;
run;
Notice that the observation containing AgeGrp='All' is not really needed; you could just as well have created another variable to collect a running total for all age groups.
If you want a procedural approach, create a format for the under 18's, then use PROC FREQ to calculate the percentage. It is necessary to exclude the 'All' values from the dataset with this method (it's generally bad practice to include summary rows in the source data).
PROC TABULATE could also be used for this.
data have;
input County $ AgeGrp $ Population;
datalines;
A 1 200
A 2 100
A 3 100
A All 400
B 1 200
B 2 300
B 3 500
B All 1000
;
run;
proc format;
value $age_fmt '1','2' = '<18'
other = '18+';
run;
proc sort data=have;
by county;
run;
proc freq data=have (where=(agegrp ne 'All')) noprint;
by county;
table agegrp / out=want (drop=COUNT where=(agegrp in ('1','2')));
format agegrp $age_fmt.;
weight population;
run;