topic Re: Do loop or array? in SAS Programming

Do loop or array?

QLi — Mon, 13 Jun 2011 18:11:01 GMT

I need count each obs non zero column,

data like this:

data a;
input m1-m12 @@;
cards;
0 1 4 0 0 0 0 0 0 0 0 0
1 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 5 0 6 0
;
run;

How can I get non zeros fro each obs?

Thanks in advance.

Re: Do loop or array?

darrylovia — Mon, 13 Jun 2011 20:00:27 GMT

Generally with an array you use some type of do loop. See my example below:

data b;
set a;

array m(12);
zero=0;
do i=1 to dim(m);
zero=zero+(m ne 0);
end;
run;

Re: Do loop or array?

SPR — Mon, 13 Jun 2011 20:31:26 GMT

Hello Darrylovia,

I am sure the summing line of your code should look like:
[pre]
zero=zero+(m[i] ne 0);
[/pre]
This is a problem of this forum software. Please, see http://support.sas.com/forums/thread.jspa?messageID=27609

Sincerely,
SPR

Re: Do loop or array?

Ankitsas — Mon, 13 Jun 2011 20:31:27 GMT

Friend,

You can use the below code to count the number of zeros in an observation

data a;
input m1-m12;
cards;
0 1 4 0 0 0 0 0 0 0 0 0
1 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 5 0 6 0
;
run;
data aa;
set a;
count = 0;
array a[12] m1-m12;
do i = 1 to 12;
if a = 0 then count+1;
end;
run;

Re: Do loop or array?

Ksharp — Tue, 14 Jun 2011 04:53:17 GMT

[pre]
data a;
input m1-m12;
cards;
0 1 4 0 0 0 0 0 0 0 0 0
1 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 5 0 6 0
;
run;
data aa;
set a;
count=0;
array a{*} m1-m12;
do i = 1 to dim(a);
if a{i} then count+1;
end;
drop i;
run;
[/pre]

Ksharp Message was edited by: Ksharp

Re: Do loop or array?

Peter_C — Wed, 15 Jun 2011 17:27:37 GMT

does this look like an opportunity for the COUNT() function?
First count all the columns in the macro environment - so counting all cols only once. On each row count occurrence of zeros to subtract from the all-cols count, leaving the non-zero count
without any arrays
Peter

Re: Do loop or array?

sbb — Wed, 15 Jun 2011 17:31:11 GMT

Although I believe that the COUNT function relates only to SAS CHARACTER type variables.

Scott Barry
SBBWorks, Inc.

Re: Do loop or array?

data_null__ — Wed, 15 Jun 2011 18:48:55 GMT

This is what I came up with using COUNT. It could be made simpler if single digits were assumed. It could also be done without the array using (of m1-m12) in the functions. Six of one, half dozen of another, arrays are just fancy variables lists.

[pre]
data test;
array m[12];
input m

;
z = cats(';',catx(',;',of m

),',');
Not0 = n(of m

)-count(z,';0,');
cards;
0 10 4 0 0 0 0 0 0 0 0 0
1 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 5 0 6 0
;;;;
run;
proc print;
run;
[/pre]

Re: Do loop or array?

chang_y_chung_hotmail_com — Wed, 15 Jun 2011 20:51:57 GMT

Here is one way that does not require neither do loops or arrays.

   data one;
      input m1-m12;
   cards;
   0 1 4 0 0 0 0 0 0 0 0 0
   1 0 0 0 0 0 0 0 0 0 0 0
   0 0 0 0 0 0 0 0 5 0 6 0
   ;
   run;

   data two;
      set one;
      zero = sum(m1=0,m2=0,m3=0,m4=0,m5=0,m6=0,
        m7=0,m8=0,m9=0,m10=0,m11=0,m12=0);
      nonzero = 12 - zero;
      put nonzero=;
   run;

Re: Do loop or array?

Peter_C — Wed, 15 Jun 2011 23:10:14 GMT

the idea of count() seems to be a bit of a failure, since the list of columns could as easily be adapted to fill the chang_y_chung solution, as any other.
for what it is worth, I was seeking

given a macro variable &names holding the list of columns to be tested for 0

%let list_count = %sysfunc( countw( &names )) ;
non_zeroes = &list_count - count( '/'!! catx( '//', of &names ) !!'/', '/0/' );

using catx() to convert the numerics in the list to character
then counting the occurrence of '/0/'