I have data like this:
data mydata;
input ID $ Val $ Date;
datalines;
1 A 2010-12-01
1 B 2010-12-03
1 A 2010-12-04
1 B 2010-12-08
2 X 2009-10-01
2 X 2009-10-02
2 Z 2009-10-03
;
run;
I would like the mode returned where it exists. ID 1, however, doesn't have a true mode. In the case of ties where modes do not exist I would like the most recent Val to break the tie (as in id 1).
Desired OUTPUT:
ID Mode
1 B
2 X
I tried proc univariate (which only handles numeric modes, another problem) but this gives the dataset with mode null; which SAS has correct but is not the desired output. I would like to do this in a datastep.
CODE:
proc univariate data=mydata noprint;
class id;
var val;
output out=modetable mode=mode;
run;
OUTPUT:
ID Mode
1
2 X
use IDgroup from proc means
An example of this statement can be fount in Identifying the Top Three Extreme Values with the Output Statistics
Let us extend the example data a little bit;
data myInput;
infile datalines dsd delimiter='09'x;
input
#1 ID 1.
#4 Val $1.
#7 Date yymmdd10.;
format Date yymmdd10.;
datalines;
2 X 2009-10-01
2 X 2009-10-02
2 Z 2009-10-03
3 C 2010-10-01
3 B 2010-10-03
3 A 2010-10-04
3 A 2010-12-01
3 B 2010-12-03
3 C 2010-12-04
;
run;
Now let us count the frequency and the last occurence of each ´Val´ for each ´ID´;
proc sql;
create view myView as
select ID, Val, max(Date) as Date format=yymmdd10., count(*) as freq
from myInput
group by ID, Val;
run;
And finally, retain one Val for each ID, prefering the more frequent one and within equally frequent ones the most recent one;
proc means data=myView nway noprint;
class ID;
output out=myModes(keep= ID Mode)
idgroup( max(freq Date) out[1] (Val)=Mode);
run;
proc print data=myModes;
run;
The result is;
ID Mode
2 X
3 C
Here is proc sql solution I came up with although I like the selected solution better:
%macro modes(data, mode , tie , break, outset , lib );
proc sql;
create table &lib..&outset as
select &id, &mode
from (select &id, &mode, latest
from(select &id, &mode, latest
from(select &id, &mode, count(*) as n, &break.(&tie) as latest
from &data
where &mode is not null
group by &id, &mode)
group by &id
having n = max(n))
group by &id
having latest= &break.(latest) )
;
quit;
%mend modes;
%modes(data=mydata, mode=age , tie=somedateorvalue , break=max, outset=outtable , lib =mylib);
Tie : is the column that is used to break ties
break : should be min or max, if you want earliest or latest date or high or low values to break ties with
The rest should be self explanatory.
Related
Here is a simple example I came up with. There are 3 players here (id is 1,2,3) and each player gets 3 attempts at the game (attempt is 1,2,3).
data have;
infile datalines delimiter=",";
input id attempt score;
datalines;
1,1,100
1,2,200
2,1,150
3,1,60
;
run;
I would like to add in rows where the score is missing if they did not play attempt 2 or attempt 3.
data want;
set have;
by id attempt;
* ??? ;
run;
proc print data=have;
run;
The output would look something like this.
1 1 100
1 2 200
1 3 .
2 1 150
2 2 .
2 3 .
3 1 60
3 2 .
3 3 .
How do I go about doing this?
You could solve this by first creating a table where you have the structure you want to see: for each ID three attempts. This structure can then be joined with a 'left join' to your 'have' table to get the actual scores if they exist and missing variable if they don't.
/* Create table with all ids for which the structure needs to be created */
proc sql;
create table ids as
select distinct id from have;
quit;
/* Create table structure with 3 attempts per ID */
data ids (drop = i);
set ids;
do i = 1 to 3;
attempt = i;
output;
end;
run;
/* Join the table structure to the actual scores in the have table */
proc sql;
create table want as
select a.*,
b.score
from ids a left join have b on a.id = b.id and a.attempt = b.attempt;
quit;
A table of possible attempts cross joined with the distinct ids left joined to the data will produce the desired result set.
Example:
data have;
infile datalines delimiter=",";
input id attempt score;
datalines;
1,1,100
1,2,200
2,1,150
3,1,60
;
data attempts;
do attempt = 1 to 3; output; end;
run;
proc sql;
create table want as
select
each_id.id,
each_attempt.attempt,
have.score
from
(select distinct id from have) each_id
cross join
attempts each_attempt
left join
have
on
each_id.id = have.id
& each_attempt.attempt = have.attempt
order by
id, attempt
;
Update: I figured it out.
proc sort data=have;
by id attempt;
data want;
set have (rename=(attempt=orig_attempt score=orig_score));
by id;
** Previous attempt number **;
retain prev;
if first.id then prev = 0;
** If there is a gap between previous attempt and current attempt, output a blank record for each intervening attempt **;
if orig_attempt > prev + 1 then do attempt = prev + 1 to orig_attempt - 1;
score = .;
output;
end;
** Output current attempt **;
attempt = orig_attempt;
score = orig_score;
output;
** If this is the last record and there are more attempts that should be included, output dummy records for them **;
** (Assumes that you know the maximum number of attempts) **;
if last.id & attempt < 3 then do attempt = attempt + 1 to 3;
score = .;
output;
end;
** Update last attempt used in this iteration **;
prev = attempt;
run;
Here is a alternative DATA step, a DOW way:
data want;
do until (last.id);
set have;
by id;
output;
end;
call missing(score);
do attempt = attempt+1 to 3;
output;
end;
run;
If the absent observations are only at the end then you can just use a couple of OUTPUT statements and a DO loop. So write each observation as it is read and if the last one is NOT attempt 3 then add more observations until you get to attempt 3.
data want1;
set have ;
by id;
output;
score=.;
if last.id then do attempt=attempt+1 to 3;
output;
end;
run;
If the absent attempts can appear any where then you need to "look ahead" to see whether the next observations skips any attempts.
data want2;
set have end=eof;
by id ;
if not eof then set have (firstobs=2 keep=attempt rename=(attempt=next));
if last.id then next=3+1;
output;
score=.;
do attempt=attempt+1 to next-1;
output;
end;
drop next;
run;
I need some help in trying to execute a comparison of rows within different ID variable groups, all in a single dataset.
That is, if there is any duplicate observation within two or more ID groups, then I'd like to delete the observation entirely.
I want to identify any duplicates between rows of different groups and delete the observation entirely.
For example:
ID Value
1 A
1 B
1 C
1 D
1 D
2 A
2 C
3 A
3 Z
3 B
The output I desire is:
ID Value
1 D
3 Z
I have looked online extensively, and tried a few things. I thought I could mark the duplicates with a flag and then delete based off that flag.
The flagging code is:
data have;
set want;
flag = first.ID ne last.ID;
run;
This worked for some cases, but I also got duplicates within the same value group flagged.
Therefore the first observation got deleted:
ID Value
3 Z
I also tried:
data have;
set want;
flag = first.ID ne last.ID and first.value ne last.value;
run;
but that didn't mark any duplicates at all.
I would appreciate any help.
Please let me know if any other information is required.
Thanks.
Here's a fairly simple way to do it: sort and deduplicate by value + ID, then keep only rows with values that occur only for a single ID.
data have;
input ID Value $;
cards;
1 A
1 B
1 C
1 D
1 D
2 A
2 C
3 A
3 Z
3 B
;
run;
proc sort data = have nodupkey;
by value ID;
run;
data want;
set have;
by value;
if first.value and last.value;
run;
proc sql version:
proc sql;
create table want as
select distinct ID, value from have
group by value
having count(distinct id) =1
order by id
;
quit;
This is my interpretation of the requirements.
Find levels of value that occur in only 1 ID.
data have;
input ID Value:$1.;
cards;
1 A
1 B
1 C
1 D
1 D
2 A
2 C
3 A
3 Z
3 B
;;;;
proc print;
proc summary nway; /*Dedup*/
class id value;
output out=dedup(drop=_type_ rename=(_freq_=occr));
run;
proc print;
run;
proc summary nway;
class value;
output out=want(drop=_type_) idgroup(out[1](id)=) sum(occr)=;
run;
proc print;
where _freq_ eq 1;
run;
proc print;
run;
A slightly different approach can use a hash object to track the unique values belonging to a single group.
data have; input
ID Value:& $1.; datalines;
1 A
1 B
1 C
1 D
1 D
2 A
2 C
3 A
3 Z
3 B
run;
proc delete data=want;
proc ds2;
data _null_;
declare package hash values();
declare package hash discards();
declare double idhave;
method init();
values.keys([value]);
values.data([value ID]);
values.defineDone();
discards.keys([value]);
discards.defineDone();
end;
method run();
set have;
if discards.find() ne 0 then do;
idhave = id;
if values.find() eq 0 and id ne idhave then do;
values.remove();
discards.add();
end;
else
values.add();
end;
end;
method term();
values.output('want');
end;
enddata;
run;
quit;
%let syslast = want;
I think what you should do is:
data want;
set have;
by ID value;
if not first.value then flag = 1;
else flag = 0;
run;
This basically flags all occurrences of a value except the first for a given ID.
Also I changed want and have assuming you create what you want from what you have. Also I assume have is sorted by ID value order.
Also this will only flag 1 D above. Not 3 Z
Additional Inputs
Can't you just do a sort to get rid of the duplicates:
proc sort data = have out = want nodupkey dupout = not_wanted;
by ID value;
run;
So if you process the observations by VALUE levels (instead of by ID levels) then you just need keep track of whether any ID is ever different than the first one.
data want ;
do until (last.value);
set have ;
by value ;
if first.value then first_id=id;
else if id ne first_id then remapped=1;
end;
if not remapped;
keep value id;
run;
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 using this SAS code:
data test1;
input cust_id $
month
category $
status $;
datalines;
A 200003 ABC C
A 200004 DEF C
A 200006 XYZ 3
B 199910 ASD X
B 199912 ASD C
;
quit;
proc sql;
create view test2 as
select cust_id, input(put(month, 6.), yymmn6.) as month format date9.,
category, status from test1 order by cust_id, month asc;
quit;
proc expand data=test2 out=test3 to=month method=none;
by cust_id;
id month;
quit;
proc print data=test3;
title "after expand";
quit;
and I want to create a dataset that looks like this:
Obs cust_id month category status
1 A 01MAR2000 ABC C
2 A 01APR2000 DEF C
3 A 01MAY2000 . .
4 A 01JUN2000 XYZ 3
5 B 01OCT1999 ASD X
6 B 01NOV1999 . .
7 B 01DEC1999 ASD C
but the output from proc expand just says "Nothing to do. The data set WORK.TEST3 has 0 observations and 0 variables." I don't want/need to change the frequency of the data, just interpolate it with missing values.
What am I doing wrong here? I think proc expand is the correct procedure to use, based on this example and the documentation, but for whatever reason it doesn't create the data.
You need to add a VAR statement. Unfortunately, the variables need to be numeric. So just expand the month by cust_id. Then join back the original values.
proc expand data=test2 out=test3 to=month ;
by cust_id;
id month;
var _numeric_;
quit;
proc sql noprint;
create table test4 as
select a.*,
b.category,
b.status
from test3 as a
left join
test2 as b
on a.cust_id = b.cust_id
and a.month = b.month;
quit;
proc print data=test4;
title "after expand";
quit;
I am trying to convert a categorical variable (Product) in binary and then want to know how many products per customer.
data is in the following format:
ID Product
C1 A
C1 B
C2 A
C3 B
C4 A
The code I am using for converting category to binary
IF PRODUCT="A" THEN PROD_A =1 ; ELSE PROD_A=0;
IF PRODUCT="B" THEN PROD_B =1 ; ELSE PROD_B=0;
TOT_PROD = SUM(PROD_A, PROD_B);
But when I count no. of product it gives me '1' for all customer and I am expecting 1 or 2.
I have tried
TOT_PROD = PROD_A + PROD_B;
but I get the same results
This is all inside one datastep, correct? If so you're processing only one line at a time. For each individual line the only possible values for PROD_A and PROD_B are one or zero. You need an aggregate function. For example, if your dataset is named PRODUCTS:
DATA X;
SET PRODUCTS;
IF PRODUCT="A" THEN PROD_A = 1 ; ELSE PROD_A=0;
IF PRODUCT="B" THEN PROD_B = 1 ; ELSE PROD_B=0;
TOT_PROD = SUM(PROD_A, PROD_B);
RUN;
(TOT_PROD will always be equal to 1 in X, but never mind for now).
Now sum them up:
proc sql;
create table prod_totals as
select product, sum(tot_prod) as total_products
from x
group by product;
quit;
More simply just skip the data step:
proc sql;
create table prod_totals as
select product, count(*) as total_products
from products
group by product;
quit;
Or use PROC SUMMARIZE or PROC MEANS instead of PROC SQL.
I have assumed you only want 1 record output per id.
In the solutions below I have employed the DOW-Loop (DO-Whitlock).
If you wanted prod_a and prod_b just to help with the totals and if they're not required in the output, then you could use something like:
data want;
do until(last.id);
set have;
by id;
tot_prod=sum(tot_prod,product='A',product='B');
end;
run;
If you need prod_a and prod_b in the output, then you could use:
data want;
do until(last.id);
set have;
by id;
prod_a=(product='A');
prod_b=(product='B');
tot_prod=sum(tot_prod,prod_a,prod_b);
end;
run;
In both data steps the last product per id will be output along with the other variables and in the case of the 2nd data step example the last prod_a & prod_b per id will also be output.
To do this in the data step, you need retain. Make sure you've sorted the dataset by id first.
data prod_totals;
set products;
by ID;
retain prod_a prod_b;
if first.id then do; *initialize to zero for each new ID;
prod_a=0; prod_b=0;
end;
if product='A' then prod_a=1; *set to 1 for each one found;
else if product='B' then prod_b=1;
if last.id then do; *for last record in each ID, output and sum total;
total_products=sum(prod_a,prod_b);
output;
end;
keep id prod_a prod_b total_products;
run;