topic Re: modify all the observations of all the variables in a dataset in SAS Programming

modify all the observations of all the variables in a dataset

Dingdang — Thu, 14 Nov 2013 09:16:55 GMT

Hi,

I used proc compare to compare the values of two data sets and put the differences into a dataset work.comp. So work.comp looks like this:

Observationtype	Observationnummer	Var1	Var3
DIF	1	-20	-10
DIF	2	100	30
DIF	3	50	-10

I want to update this table with the following rules: for all the variables, if the observation is bigger than 0, then replace the observationvalue with '1' else replace with '0'.

the example above will then look like this:

Observationtype	Header 2	Var1	Var3
DIF	1	0	0
DIF	2	1	1
DIF	3	1	0

Many many thanks again for the help!

BR Dingdang

Re: modify all the observations of all the variables in a dataset

pradeepalankar — Thu, 14 Nov 2013 09:45:45 GMT

data work.comp;

set work.comp ;

if var1<=0 then var1=0 ;else var1=1;

if var2<=0 then var2=0 ;else var2=1;

if var3<=0 then var3=0 ;else var3=1;

;run;

proc print;run;

Re: modify all the observations of all the variables in a dataset

Jagadishkatam — Thu, 14 Nov 2013 10:16:22 GMT

alternatively, if you have many variables to change then arrays will be a good option

data want;

set have;

array vars(*) var1 - var3;

do i =1 to dim(vars);

if vars(i) > 0 then vars(i)=1;

else vars(i)=0;

end;

run;

Thanks,

jagadish

Re: modify all the observations of all the variables in a dataset

Dingdang — Thu, 14 Nov 2013 12:49:04 GMT

hi Jagadish,

this is exactly what i am looking for. I wrote sth. similar but i used {} instead of () to address the elements in the array. I think I need to look into the differences between () [] and {}.

Thanks again. BR Dingdang

Re: modify all the observations of all the variables in a dataset

Amir — Thu, 14 Nov 2013 12:54:10 GMT

Hi,

A slight variation on the response supplied by :

data want;

set have;

drop i;

array vars(*) var1 - var3;

do i =1 to dim(vars);

vars(i)=vars(i) > 0;

end;

run;

Regards,

Amir.

Re: modify all the observations of all the variables in a dataset

Dingdang — Thu, 14 Nov 2013 15:15:35 GMT

thanks, the "drop i" is good.

Re: modify all the observations of all the variables in a dataset

Amir — Thu, 14 Nov 2013 17:09:06 GMT

Hi,

Yes, the drop is good, but, in case it was not noticed, the main change was the absence of any if-then-else statement.

Regards,

Amir.

Re: modify all the observations of all the variables in a dataset

Dingdang — Thu, 14 Nov 2013 17:33:59 GMT

Hey Amir,

hehe, thanks for pointing that out. as you correctly noticed, i didnt notice that learned sth. new again, have to look into that when i finish the current task...

have a great day. Dingdang