[R] Odp: Counting rows given conditional

[Petr PIKAL]

Hi

r-help-bounces at r-project.org napsal dne 04.08.2011 14:56:09:

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> [R] Counting rows given conditional
> 
> Hello,
> 
> I have an input file that contains multiple columns, but the column I'm
> concerned about looks like:
> 
> "TR"
> 5
> 0
> 4
> 1
> 0
> 2
> 0
> 
> To count all of the rows in the column I know how to do NROW(x$TR) which
> gives 7.
> 
> However, I would also like to count only the number of rows with values 
>=1
> (i.e. not 0). I've tried NROW(x$TR>=1) which did not give the intended
> output.

You are quite close. 
x$TR>=1
gives you logical vector TRUE/FALSE. You can compute count of TRUE values 
by
sum(logical.vector) e.g.
sum(x$TR>=1)

Regards
Petr



> 
> Do any of you have any suggestions as to where I'm going wrong?
> 
> 
> 
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