[R] How to extract integer in a data frame

[Duncan Murdoch]

On 21/04/2009 8:52 PM, Gundala Viswanath wrote:
> Dear all,
> 
> I have a data frame that looks like this:
> 
>> dat
> 
>               V1      V2      V3
> 1          0.000       2 554889
> 2          2.001       0    9978
> 3          0.342       3    5263
> 4          123.000      0    3209
> 5          0.004       0    2434
> 
> 
> I want to get a subset of that data frame where
> the entry in V1 has (x.000) as its decimal.
> 
> yielding
> 
>> wanted_dat
>               V1      V2      V3
> 1          0.000       2 554889
> 2          123.000   0    3209
> 
> What's the way to do it in R?
> 
> - Gundala Viswanath
> Jakarta - Indonesia
> 

If you know that those values are really integers, you could use

dat[ dat$V1 == round(dat$V1), ]

but if you just want the printed version to have three zeroes after the 
decimal point, you'll want something with grep, e.g.

dat[ grep("[.]000$", format(dat$V1)), ]

(These are both untested.)

Duncan Murdoch