[R] Re : Re: setting a number of values to NA over a data.frame.

[Prof Brian Ripley]

I think you do understand it. Indexing a data frame by a logical matrix is 
provided just for applications like this and the reverse,

mydf[is.na(mydf)]  <- something

prettyR's toNA seems to believe that data frames can be other than 2D, 
which is surprising.

On Thu, 8 Feb 2007, Olivier ETERRADOSSI wrote:

> Hi John,
>
> Unless I miss a point, why dont you try something like :
>
> # some fake data
> > fake<-as.data.frame(cbind(seq(1,10,by=1),c(rep(1,4),rep(0,4),rep(2,2))))
>      V1 V2
> 1    1    1
> 2    2    1
> 3    3    1
> 4    4    1
> 5    5    0
> 6    6    0
> 7    7    0
> 8    8    0
> 9    9    2
> 10   10    2
>
> # change 0 by NA
> > fake[fake==0]<-NA  # or fake$V2[fake$V2==0]<-NA if you don't want all
> 0 in the dataframe to be changed to NA
> # test
> > is.na(fake$V2)
> [1] FALSE FALSE FALSE FALSE  TRUE  TRUE  TRUE  TRUE FALSE FALSE
>
> Sorry if I did not understand the issue. Hope this helps. Olivier
>
>
> Jim Lemon wrote :
>
>> John Kane wrote:
>>
>>>> This is probably a simple problem but I don't see a
>>>> solution.
>>>>
>>>> I have a data.frame with a number of columns where I
>>>> would like 0 <- NA
>>>>
>>>
>> Hi John,
>> You might have a look at "toNA" in the prettyR package. Wait for version
>> 1.0-4, just uploaded, as I have fixed a bug in that function.
>>
>> Jim
>
>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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