Re: [R] trouble understanding why ...=="NaN" isn't true
Hi, Andrew,
Looks like you're reading the data incorrectly. If using ?read.table or
the like, try to add a na.strings = c("NA", "NaN") argument. Second,
Bert's comment: use ?is.nan, rather than "==".
--sundar
Andrew Yee said the following on 5/29/2007 3:39 PM:
> Okay, it turns out that there were leading spaces, so that in the data, it
> was represented as " NaN", hence the expression =="NaN" was coming back as
> false.
>
> Is there a way to find out preemptively if there are leading spaces?
>
> Thanks,
> Andrew
>
>
> On 5/29/07, Andrew Yee <[EMAIL PROTECTED]> wrote:
>> I have the following data:
>>
>>> dataset[2,"Sample.227"]
>> [1]NaN
>> 1558 Levels: -0.000 -0.001 -0.002 -0.003 -0.004 -0.005 -0.006 -0.007 -
>> 0.008 -0.009 ... 2.000
>>
>>
>> However, I'm not sure why this expression is coming back as FALSE:
>>
>>> dataset[2,"Sample.227"]=="NaN"
>> [1] FALSE
>>
>> Similarly:
>>
>>> dataset[2,"Sample.227"]==NaN
>> [1] NA
>>
>>
>> It seems that since "NaN" is represented as a character, this expression
>> =="NaN" should be TRUE, but it's returning as FALSE.
>>
>> Thanks,
>> Andrew
>>
>
> [[alternative HTML version deleted]]
>
> __
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
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Re: [R] trouble understanding why ...=="NaN" isn't true
1. "NaN" is a character string, **not** NaN; hence is.nan("NaN") yields
FALSE.
2. Please read the docs! ?NaN explicitly says:
"Do not test equality to NaN, or even use identical, since systems typically
have many different NaN values."
Bert Gunter
Genentech Nonclinical Statistics
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Andrew Yee
Sent: Tuesday, May 29, 2007 3:33 PM
To: r-help@stat.math.ethz.ch
Subject: [R] trouble understanding why ...=="NaN" isn't true
I have the following data:
> dataset[2,"Sample.227"]
[1]NaN
1558 Levels: -0.000 -0.001 -0.002 -0.003 -0.004 -0.005 -0.006 -0.007 -0.008-
0.009 ... 2.000
However, I'm not sure why this expression is coming back as FALSE:
> dataset[2,"Sample.227"]=="NaN"
[1] FALSE
Similarly:
> dataset[2,"Sample.227"]==NaN
[1] NA
It seems that since "NaN" is represented as a character, this expression
=="NaN" should be TRUE, but it's returning as FALSE.
Thanks,
Andrew
[[alternative HTML version deleted]]
__
R-help@stat.math.ethz.ch 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.
__
R-help@stat.math.ethz.ch 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.
Re: [R] trouble understanding why ...=="NaN" isn't true
Okay, it turns out that there were leading spaces, so that in the data, it was represented as " NaN", hence the expression =="NaN" was coming back as false. Is there a way to find out preemptively if there are leading spaces? Thanks, Andrew On 5/29/07, Andrew Yee <[EMAIL PROTECTED]> wrote: > > I have the following data: > > > dataset[2,"Sample.227"] > [1]NaN > 1558 Levels: -0.000 -0.001 -0.002 -0.003 -0.004 -0.005 -0.006 -0.007 - > 0.008 -0.009 ... 2.000 > > > However, I'm not sure why this expression is coming back as FALSE: > > > dataset[2,"Sample.227"]=="NaN" > [1] FALSE > > Similarly: > > > dataset[2,"Sample.227"]==NaN > [1] NA > > > It seems that since "NaN" is represented as a character, this expression > =="NaN" should be TRUE, but it's returning as FALSE. > > Thanks, > Andrew > [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch 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.
[R] trouble understanding why ...=="NaN" isn't true
I have the following data: > dataset[2,"Sample.227"] [1]NaN 1558 Levels: -0.000 -0.001 -0.002 -0.003 -0.004 -0.005 -0.006 -0.007 -0.008- 0.009 ... 2.000 However, I'm not sure why this expression is coming back as FALSE: > dataset[2,"Sample.227"]=="NaN" [1] FALSE Similarly: > dataset[2,"Sample.227"]==NaN [1] NA It seems that since "NaN" is represented as a character, this expression =="NaN" should be TRUE, but it's returning as FALSE. Thanks, Andrew [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch 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.
