## What is the array command for alternative oberservations?

Occasional Contributor
Posts: 6

# What is the array command for alternative oberservations?

Hi everyone.

If I got a data like:

1 1 4 6 7 3 2 5 7 8 9 5 3 2 6 8 9 0 9 0 9 7 6 5 4 5 7 8 9 8

how can i put them into different arrays alternatively? like the first, third, fifth, seventh.....,29th (the number of obeservation = old) in one group and the second, forth, sixth,....,30th (the number of obersvation = even) in another group.

Thank you

Super User
Posts: 8,120

## What is the array command for alternative oberservations?

What do you really want to do?  I don't think that ARRAY (as used in SAS) has anything to do with your problem.

If you want to read in a series of numbers into two variables (call them ODD and EVEN) then you can do it this way.

data want;

input odd even @@;

cards;

1 1 4 6 7 3 2 5 7 8 9 5 3 2 6 8 9 0 9 0 9 7 6 5 4 5 7 8 9 8

;;;;

proc print; run;

Obs    odd    even

1     1       1

2     4       6

3     7       3

4     2       5

5     7       8

6     9       5

7     3       2

8     6       8

9     9       0

10     9       0

11     9       7

12     6       5

13     4       5

14     7       8

15     9       8

Occasional Contributor
Posts: 6

## What is the array command for alternative oberservations?

My question mainly is I would like to group the 1st, 3rd, 5th, 7th, 9th,....,29th obervation in ONE group called "A"

then another group called "B" for the 2nd, 4th, 6th,..., 30th obeservation.

I would like to use the array function to do this.

Thanks

PROC Star
Posts: 8,165

## What is the array command for alternative oberservations?

Tom is probably right but, if you already have the file and need to split the variables into two groups, you could use something like:

data have;

input x1-x30;

cards;

1 1 4 6 7 3 2 5 7 8 9 5 3 2 6 8 9 0 9 0 9 7 6 5 4 5 7 8 9 8

;

data want;

set have;

array all(*) x1-x30;

array odd(15);

array even(15);

do i=1 to dim(all)-1 by 2;

j+1;

odd(j)=all(i);

even(j)=all(i+1);

end;

run;

Occasional Contributor
Posts: 6

## What is the array command for alternative oberservations?

But i actually got 1044 data, is there a way that I can avoid typing that 1044 data for this command as in the 7th line of your reply? (the line under cards

Occasional Contributor
Posts: 6

## What is the array command for alternative oberservations?

And how can i name them in array called A and B? thanks

PROC Star
Posts: 8,165

## What is the array command for alternative oberservations?

I'm unclear about your data.  Do you have something like 1044 records with one variable each, or one (or more) record(s) with each containing 1044 variables?

In either case, what are the actual variable names?

Occasional Contributor
Posts: 6

## What is the array command for alternative oberservations?

I do have 1044 data, which the data are alternatively placed (1st data - group A, 2nd data - group B, 3rd data - group A, .... , 1044th data - group B)

thank you

PROC Star
Posts: 8,165

## What is the array command for alternative oberservations?

I'm still unclear about what you have and what you want to have.  Does the following describe your data and a possible solution?

data have;

input data;

cards;

1

1

4

6

7

3

2

5

7

8

9

5

3

2

6

8

9

0

9

0

9

7

6

5

4

5

7

8

9

8

;

data want;

set have;

retain groupA;

if mod(_n_,2) then groupA=data;

else do;

groupB=data;

output;

end;

run;

Posts: 3,167

## What is the array command for alternative oberservations?

When you mention that you have 1044 data, do you mean you have 1044 columns (variables) or 1044 rows (records)? Either way, I think you already have great answers, unless your '1044 data' means otherwise, which you need to let us know, perferably with some sample data.

Haikuo

Super Contributor
Posts: 1,636

## Re: What is the array command for alternative oberservations?

Is this what you want?

data have;

input v1;

cards;

1

1

4

6

7

3

2

5

7

8

9

5

3

2

6

8

9

0

9

0

9

7

6

5

4

5

7

8

9

8

;

data temp;

length group \$ 1;

set have;

n=_n_;

if mod(_n_,2) then group='A';

else group='B';

run;

proc sort;by group n;run;

proc transpose data=temp out=want ;

var v1;

run;

data want;

set want;

array A(*) col1-col15;

array B(*) col16-col30;

do i=1 to 15;

total_A +A(i);

total_B +B(i);

end;

run;

proc print;run;

Super User
Posts: 8,120

## What is the array command for alternative oberservations?

If you want to create assign alternate observations to groups .

data want ;

retain group ;

set have;

if group='A' then group='B';

else group='A';

run;

Obs    group    odd    even

1      A       1       1

2      B       4       6

3      A       7       3

4      B       2       5

5      A       7       8

6      B       9       5

7      A       3       2

8      B       6       8

9      A       9       0

10      B       9       0

11      A       9       7

12      B       6       5

13      A       4       5

14      B       7       8

15      A       9       8

Super User
Posts: 10,784

## Re: What is the array command for alternative oberservations?

It looks like OP did not make himself clear.

```data have;
input value @@;
cards;
1 1 4 6 7 3 2 5 7 8 9 5 3 2 6 8 9 0 9 0 9 7 6 5 4 5 7 8 9 8
;
run;
%let dsid=%sysfunc(open(have));
%let n=%sysevalf(%sysfunc(attrn(&dsid,nobs))/2,ceil);
%let dsid=%sysfunc(close(&dsid));

data _null_;
set have end=last;
array odd{&n} _temporary_;
array even{&n} _temporary_;
if mod(_n_,2) eq 1 then do; a+1;odd{a}=value;end;
else do; b+1;even{b}=value;end;

if last then do;
do i=1 to &n;
put odd{i}= even{i}=;
end;
end;
run;

```

Ksharp

Tian.Kong

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