drop observations

On Dec 30, 2010, at 4:54 PM, Charl?ne Cosandier wrote:

Hi,

I want to drop observations with value 0 from my data.frame "dta"  
for each
of the two variables "c01" and "ctotale". How can I do that?

And on second look I wonder if my translation from English to Boolean  
was correct. If you wanted to excluded any case with c01 == 0 or  
ctotal==0 then the code was correct, but if you wanted to exclude only  
case where both were zero, the code would be incorrect and the logical  
operator should be changed to "&".

Thanks

subset(dta, !( c01==0 | ctotale==0) )

... remembering of course to assign this result to some  
appropriately named object.

Charl?ne Lisa Cosandier

David Winsemius, MD
West Hartford, CT