R help - May 2011 - NaN, Inf to NA

Hi,

I want to recode all Inf and NaN values to NA, but I;m surprised to see the 
result of the following code. Could anybody enlighten me about this? 
> df <- data.frame(a=c(NA, NaN, Inf, 1:3))
> df[is.infinite(df) | is.nan(df)] <- NA
> df
    a
1  NA
2 NaN
3 Inf
4   1
5   2
6   3
> 
 
Thanks!

Cheers!!
Albert-Jan


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All right, but apart from the sanitation, the medicine, education, wine, public 
order, irrigation, roads, a fresh water system, and public health, what have the
Romans ever done for us?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	[[alternative HTML version deleted]]

> df$a[is.infinite(df$a) | is.nan(df$a) ] <- NA
> df
   a
1 NA
2 NA
3 NA
4  1
5  2
6  3


On 5/26/11 3:18 PM, "Albert-Jan Roskam" <fomcl at yahoo.com>
wrote:
>Hi,
>
>I want to recode all Inf and NaN values to NA, but I;m surprised to see
>the 
>result of the following code. Could anybody enlighten me about this?
>
>> df <- data.frame(a=c(NA, NaN, Inf, 1:3))
>> df[is.infinite(df) | is.nan(df)] <- NA
>> df
>    a
>1  NA
>2 NaN
>3 Inf
>4   1
>5   2
>6   3
>> 
>
> 
>Thanks!
>
>Cheers!!
>Albert-Jan
>
>
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>All right, but apart from the sanitation, the medicine, education, wine,
>public 
>order, irrigation, roads, a fresh water system, and public health, what
>have the 
>Romans ever done for us?
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>	[[alternative HTML version deleted]]
>
>______________________________________________
>R-help at r-project.org mailing list
>https://stat.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide
>http://www.R-project.org/posting-guide.html
>and provide commented, minimal, self-contained, reproducible code.

On May 26, 2011, at 3:18 PM, Albert-Jan Roskam wrote:
> Hi,
> 
> I want to recode all Inf and NaN values to NA, but I;m surprised to see the
> result of the following code. Could anybody enlighten me about this? 
> 
>> df <- data.frame(a=c(NA, NaN, Inf, 1:3))
>> df[is.infinite(df) | is.nan(df)] <- NA
>> df
>    a
> 1  NA
> 2 NaN
> 3 Inf
> 4   1
> 5   2
> 6   3
>> 
> 
> 
> Thanks!
> 
> Cheers!!
> Albert-Jan

The canonical way is to use is.na() to assign the NA value based upon a
condition. See ?is.na for more information.

is.na(df$a) <- !is.finite(df$a)
> df
   a
1 NA
2 NA
3 NA
4  1
5  2
6  3


HTH,

Marc Schwartz