How to easly reformat dataset in SAS - sas

Suppose a data are as follows:
A B C
1 3 2
1 4 9
2 6 0
2 7 3
where A B and C are the variable names.
Is there a way to transform the table to
A 1
A 1
A 2
A 2
B 3
B 4
B 6
B 7
C 2
C 9
C 0
C 3

Expanding on the advice from #donPablo, here's how you would code it. Create an array to read across the data, then output each iteration of that array so you end up with the number of rows being the rows * columns from the original dataset. The VNAME function enables you to store the variable name (A, B, C) as a value in a separate variable.
data have;
input A B C;
datalines;
1 3 2
1 4 9
2 6 0
2 7 3
;
run;
data want;
set have;
length var1 $10;
array vars{*} _numeric_;
do i=1 to dim(vars);
var1=vname(vars{i});
var2=vars{i};
keep var1 var2;
output;
end;
run;
proc sort data=want;
by var1;
run;

The least amount of (expensive) development time might be --
Read and store the first row
For each subsequent row
Read the row
Create three records
Until end
Sort
How many times will this be run? Per day/ per year?
What number of rows are there?
Might we save 1 hr / month? 1 min / year? Something will need to read the entire file. Optomize last. Make it work first.
tkx

It should work correctly:
DATA A(keep A);
new_var = 'A';
SET your_data;
RUN;
DATA B(keep B);
new_var = 'B';
SET your_data;
RUN;
DATA C(keep C);
new_var = 'C';
SET your_data;
RUN;
PROC APPEND base=A data=B FORCE;
RUN;
PROC APPEND base=A data=C FORCE;
RUN;
Data A is a result data set.

Related

Aggregate multiple vars on different groupings in one Proc SQL query

I need to aggregate about ten different vars on different groupings using Proc SQL;
Is there a way to achieve SUM () OVER ( [ partition_by_clause ] order_by_clause) in one sql query with different partition by clauses.
I've made an example here
data have;
infile cards;
input a b c d e f;
cards;
1 2 3 4 5
2 2 4 5 6
1 4 3 4 7
3 4 4 5 8
;
run;
proc sql;
create table want as
select *,
sum a over partiton by (b,c) as a1,
sum b over partiton by (c,d) as b1
sum c over partiton by (d,e) as c1
sum d over partiton by (a,c) as d1
from have
;
quit;
I don't want to wirte multiple sql queries and grouping on different vars and calculating one var in each step.
Hope that makes sense.
Proc SQL does not implement windowing functions and thus partition syntax therein as found in other SQL implementations. You can only do partition by with passthrough SQL to a connection that allows such syntax.
You could perform such a computation in DATA step using hashes.
data have;
infile cards;
input a b c d e ;
cards;
1 2 3 4 5
2 2 4 5 6
1 4 3 4 7
3 4 4 5 8
;
run;
data want;
if 0 then set have;
length a1 b1 c1 d1 8;
declare hash a1s();
a1s.defineKey('b', 'c');
a1s.defineData('a1');
a1s.defineDone();
declare hash b1s();
b1s.defineKey('c', 'd');
b1s.defineData('b1');
b1s.defineDone();
declare hash c1s();
c1s.defineKey('d', 'e');
c1s.defineData('c1');
c1s.defineDone();
declare hash d1s();
d1s.defineKey('a', 'c');
d1s.defineData('d1');
d1s.defineDone();
do while (not end);
set have end=end;
if a1s.find() = 0 then a1+a; else a1=a; a1s.replace();
if b1s.find() = 0 then b1+b; else b1=b; b1s.replace();
if c1s.find() = 0 then c1+c; else c1=c; c1s.replace();
if d1s.find() = 0 then d1+d; else d1=d; d1s.replace();
end;
do while (not last);
set have end=last;
a1s.find();
b1s.find();
c1s.find();
d1s.find();
output;
end;
format _numeric_ 4.;
stop;
run;

SAS 9.4 Replacing all values after current line based on current values

I am matching files base on IDs numbers. I need to format a data set with the IDs to be matched, so that the same ID number is not repeated in column a (because column b's ID is the surviving ID after the match is completed). My list of IDs has over 1 million observations, and the same ID may be repeated multiple times in either/both columns.
Here is an example of what I've got/need:
Sample Data
ID1 ID2
1 2
3 4
2 5
6 1
1 7
5 8
The surviving IDs would be:
2
4
5
error - 1 no longer exists
error - 1 no longer exists
8
WHAT I NEED
ID1 ID2
1 2
3 4
2 5
6 5
5 7
7 8
I am, probably very obviously, a SAS novice, but here is what I have tried, re-running over and over again because I have some IDs that are repeated upward of 50 times or more.
Proc sort data=Have;
by ID1;
run;
This sort makes the repeated ID1 values consecutive, so the I could use LAG to replace the destroyed ID1s with the surviving ID2 from the line above.
Data Want;
set Have;
by ID1;
lagID1=LAG(ID1);
lagID2=LAG(ID2);
If NOT first. ID1 THEN DO;
If ID1=lagID1 THEN ID1=lagID2;
KEEP ID1 ID2;
IF ID1=ID2 then delete;
end;
run;
That sort of works, but I still end up with some that end up with duplicates that won't resolve no matter how many times I run (I would have looped it, but I don't know how), because they are just switching back and forth between IDs that have other duplicates (I can get down to about 2,000 of these).
I have figured out that instead of using LAG, I need replace all values after the current line with ID2 for each ID1 value, but I cannot figure out how to do that.
I want to read observation 1, find all later instances of the value of ID1, in both ID1 or ID2 columns, and replace that value with the current observation's ID2 value. Then I want to repeat that process with line 2 and so on.
For the example, I would want to look for any instances after line one of the value 1, and replace it with 2, since that is the surviving ID of that pair - 1 may appear further down multiple times in either of the columns, and I need all them to replaced. Line two would look for later values of 3 and replace them with 4, and so one. The end result should be that an ID number only appears once ever in the ID1 column (though it may appear multiple times in the ID2 column).
ID1 ID2
1 2
3 4
2 5
6 1
1 7
5 8
After first line has been read, data set would look as follows:
ID1 ID2
1 2
3 4
2 5
6 2
2 7
5 8
Reading observation two would make no changes since 3 does not appear again; after observation 3, the set would be:
ID1 ID2
1 2
3 4
2 5
6 5
5 7
5 8
Again, there would be not changes from observation four. but observation 5 would cause the final change:
ID1 ID2
1 2
3 4
2 5
6 5
5 7
7 8
I have tried using the following statement but I can't even tell if I am on the complete wrong track or if I just can't get the syntax figured out.
Data want;
Set have;
Do i=_n_;
ID=ID2;
Replace next var{EUID} where (EUID1=EUID1 AND EUID2=EUID1);
End;
Run;
Thanks for your help!
There is no need to work back and forth thru the data file. You just need to retain the replacement information so that you can process the file in a single pass.
One way to do that is to make a temporary array using the values of the ID variables as the index. That is easy to do for your simple example with small ID values.
So for example if all of the ID values are integers between 1 and 1000 then this step will do the job.
data want ;
set have ;
array xx (1000) _temporary_;
do while (not missing(xx(id1))); id1=xx(id1); end;
do while (not missing(xx(id2))); id2=xx(id2); end;
output;
xx(id1)=id2;
run;
You probably need to add a test to prevent cycles (1 -> 2 -> 1).
For a more general solution you should replace the array with a hash object instead. So something like this:
data want ;
if _n_=1 then do;
declare hash h();
h.definekey('old');
h.definedata('new');
h.definedone();
call missing(new,old);
end;
set have ;
do while (not h.find(key:id1)); id1=new; end;
do while (not h.find(key:id2)); id2=new; end;
output;
h.add(key: id1,data: id2);
drop old new;
run;
Here's an implementation of the algorithm you've suggested, using a modify statement to load and rewrite each row one at a time. It works with your trivial example but with messier data you might get duplicate values in ID1.
data have;
input ID1 ID2 ;
datalines;
1 2
3 4
2 5
6 1
1 7
5 8
;
run;
title "Before making replacements";
proc print data = have;
run;
/*Optional - should improve performance at cost of increased memory usage*/
sasfile have load;
data have;
do i = 1 to nobs;
do j = i to nobs;
modify have point = j nobs = nobs;
/* Make copies of target and replacement value for this pass */
if j = i then do;
id1_ = id1;
id2_ = id2;
end;
else do;
flag = 0; /* Keep track of whether we made a change */
if id1 = id1_ then do;
id1 = id2_;
flag = 1;
end;
if id2 = id1_ then do;
id2 = id2_;
flag = 1;
end;
if flag then replace; /* Only rewrite the row if we made a change */
end;
end;
end;
stop;
run;
sasfile have close;
title "After making replacements";
proc print data = have;
run;
Please bear in mind that as this modifies the dataset in place, interrupting the data step while it is running could result in data loss. Make sure you have a backup first in case you need to roll your changes back.
Seems like this should do the trick and is fairly straight forward. Let me know if it is what you are looking for:
data have;
input id1 id2;
datalines;
1 2
3 4
2 5
6 1
1 7
5 8
;
run;
%macro test();
proc sql noprint;
select count(*) into: cnt
from have;
quit;
%do i = 1 %to &cnt;
proc sql noprint;
select id1,id2 into: id1, :id2
from have
where monotonic() = &i;quit;
data have;
set have;
if (_n_ > input("&i",8.))then do;
if (id1 = input("&id1",8.))then id1 = input("&id2",8.);
if (id2 = input("&id1",8.))then id2 = input("&id2",8.);
end;
run;
%end;
%mend test;
%test();
this might be a little faster:
data have2;
input id1 id2;
datalines;
1 2
3 4
2 5
6 1
1 7
5 8
;
run;
%macro test2();
proc sql noprint;
select count(*) into: cnt
from have2;
quit;
%do i = 1 %to &cnt;
proc sql noprint;
select id1,id2 into: id1, :id2
from have2
where monotonic() = &i;
update have2 set id1 = &id2
where monotonic() > &i
and id1 = &id1;
quit;
proc sql noprint;
update have2 set id2 = &id2
where monotonic() > &i
and id2 = &id1;
quit;
%end;
%mend test2;
%test2();

SAS concatenate in SAS Data Step

I don't know how to describe this question but here is an example. I have an initial dataset looks like this:
input first second $3.;
cards;
1 A
1 B
1 C
1 D
2 E
2 F
3 S
3 A
4 C
5 Y
6 II
6 UU
6 OO
6 N
7 G
7 H
...
;
I want an output dataset like this:
input first second $;
cards;
1 "A,B,C,D"
2 "E,F"
3 "S,A"
4 "C"
5 "Y"
6 "II,UU,OO,N"
7 "G,H"
...
;
Both tables will have two columns. Unique value of range of the column "first" could be 1 to any number.
Can someone help me ?
something like below
proc sort data=have;
by first second;
run;
data want(rename=(b=second));
length new_second $50.;
do until(last.first);
set have;
by first second ;
new_second =catx(',', new_second, second);
b=quote(strip(new_second));
end;
drop second new_second;
run;
output is
first second
1 "A,B,C,D"
2 "E,F"
3 "A,S"
4 "C"
5 "Y"
6 "II,N,OO,UU"
7 "G,H"
You can use by-group processing and the retain function to achieve this.
Create a sample dataset:
data have;
input id value $3.;
cards;
1 A
1 B
1 C
1 D
2 E
2 F
3 S
3 A
4 C
5 Y
6 II
6 UU
6 OO
6 N
7 G
7 H
;
run;
First ensure that your dataset is sorted by your id variable:
proc sort data=have;
by id;
run;
Then use the first. and last. notation to identify when the id variable is changing or about to change. The retain statement tells the datastep to keep the value within concatenated_value over observations rather than resetting it to a blank value. Use the quote() function to apply the " chars around the result before outputting the record. Use the cats() function to perform the actual concatenation and separate the records with a ,.
data want;
length contatenated_value $500.;
set have;
by id;
retain contatenated_value ;
if first.id then do;
contatenated_value = '';
end;
contatenated_value = catx(',', contatenated_value, value);
if last.id then do;
contatenated_value = quote(cats(contatenated_value));
output;
end;
drop value;
run;
Output:
contatenated_
value id
"A,B,C,D" 1
"E,F" 2
"S,A" 3
"C" 4
"Y" 5
"II,UU,OO,N" 6
"G,H" 7

SAS MACRO: Create many datasets -modify them - combine them into one within one MACRO without need to ouput multiple datsets

My initial Dataset has 14000 STID variable with 10^5 observation for each.
I would like to make some procedures BY each stid, output the modification into data by STID and then set all STID together under each other into one big dataset WITHOUT a need to output all temporary STID-datsets.
I start writing a MACRO:
data HAVE;
input stid $ NumVar1 NumVar2;
datalines;
a 5 45
b 6 2
c 5 3
r 2 5
f 4 4
j 7 3
t 89 2
e 6 1
c 3 8
kl 1 6
h 2 3
f 5 41
vc 58 4
j 5 9
ude 7 3
fc 9 11
h 6 3
kl 3 65
b 1 4
g 4 4
;
run;
/* to save all distinct values of THE VARIABLE stid into macro variables
where &N_VAR - total number of distinct variable values */
proc sql;
select count(distinct stid)
into :N_VAR
from HAVE;
select distinct stid
into :stid1 - :stid%left(&N_VAR)
from HAVE;
quit;
%macro expand_by_stid;
/*STEP 1: create datasets by STID*/
%do i=1 %to &N_VAR.;
data stid&i;
set HAVE;
if stid="&&stid&i";
run;
/*STEP 2: from here data modifications for each STID-data (with procs and data steps, e.g.)*/
data modified_stid&i;
set stid&i;
NumVar1_trans=NumVar1**2;
NumVar2_trans=NumVar1*NumVar2;
run;
%end;
/*STEP 3: from here should be some code lines that set together all created datsets under one another and delete them afterwards*/
data total;
set %do n=1 %to &N_VAR.;
modified_stid&n;
%end;
run;
proc datasets library=usclim;
delete <ALL DATA SETS by SPID>;
run;
%mend expand_by_stid;
%expand_by_stid;
But the last step does not work. How can I do it?
You're very close - all you need to do is remove the semicolon in the macro loop and put it after the %end in step 3, as below:
data total;
set
%do n=1 %to &N_VAR.;
modified_stid&n
%end;;
run;
This then produces the statement you were after:
set modified_stid1 modified_stid2 .... ;
instead of what your macro was originally generating:
set modified_stid1; modified_stid2; ...;
Finally, you can delete all the temporary datasets using stid: in the delete statement:
proc datasets library=usclim;
delete stid: ;
run;

SAS sort by original order

Say you have three separate data sets consisting of the same number of observations. Each observation has an ID letter, A-Z, followed by some numerical observation. For example:
Data set 1:
B 3 8 1 9 4
C 4 1 9 3 1
A 4 4 5 4 9
Data set 2:
C 3 1 9 4 0
A 4 1 2 0 0
B 0 3 3 1 8
I want to merge the data sets BY that first variable. The problem is, the first variable is NOT already sorted in alphabetical form, and I do not want to sort it in alphabetical form. I want to merge the data but keep the original order. For example, I would get:
Merged data:
B 3 8 1 9 4
B 0 3 3 1 8
C 4 1 9 3 1
C 3 1 9 4 0
A 4 4 5 4 9
A 4 1 2 0 0
Is there any way to do this?
You can create a variable that holds the order and then apply that the new dataset after its "merged". I believe this is an append rather than merge though. I've used a format, though you could use a sql or data set merge as well.
data have1;
input id $ var1-var5;
cards;
B 3 8 1 9 4
C 4 1 9 3 1
A 4 4 5 4 9
;
run;
data have2;
input id $ var1-var5;
cards;
C 3 1 9 4 0
A 4 1 2 0 0
B 0 3 3 1 8
;
run;
data order;
set have1;
fmtname='sort_order';
type='J';
label=_n_;
start=id;
keep id fmtname type label start;
run;
proc format cntlin=order;
run;
data want;
set have1 have2;
order_var=input(id, $sort_order.);
run;
proc sort data=want;
by order_var;
run;
This is just one SQL version which follows along a similar path to Joe's answer. Row order is input via a sub-query rather than a format. However the initial order of the two input tables is lost in the join to the row order sub-query. The original order (have2 follows have1) is re-instated by using the table names as a secondary order variable.
proc sql;
create table want1 as
select want.id
,want.var1
,want.var2
,want.var3
,want.var4
,want.var5
from (
select *
, 'have1' as source
from have1
union all
select *
, 'have2' as source
from have2
) as want
left join
(
select id
, monotonic() as row_no
from have1
) as order
on want.id eq order.id
order by order.row_no
,want.source
;
quit;
proc compare
base=want1
compare=want
;
run;
And this is a data step version without a format. Here the have1 table with row order is re-merged with the concatenated data (have1 and have2) and then re-sorted by row order.
data want2;
set have1 have2;
run;
data have1;
set have1;
order_var = _n_;
run;
proc sort data=want2;
by id;
run;
proc sort data=have1;
by id;
run;
data want2;
merge want2 have1;
by id;
run;
proc sort data=want2;
by order_var;
run;
proc compare
base=want2
compare=want
;
run;