thr3ads.net - R help - [R] Problem with <= (less than or equal): not giving the expected result [Apr 2016]

If this information is useful, please help other people find it:
Share via:

Rainer Johannes

2016-Apr-05 12:46 UTC

[R] Problem with <= (less than or equal): not giving the expected result

Thanks Adrian and Thierry (from the previous answer).

I was aware of the all.equal function, but there is nothing similar for <=
(e.g. all.smallerEqual)?

cheers, jo

On 05 Apr 2016, at 14:31, Adrian Du?a <dusa.adrian at
unibuc.ro<mailto:dusa.adrian at unibuc.ro>> wrote:

Yes, that does have to do with floating point representation.
I use this function for these types of comparisons (works with values as well as
with vectors):

check.equal <- function(x, y) {
    check.vector <- as.logical(unlist(lapply(x, all.equal, y)))
    check.vector[is.na<http://is.na/>(check.vector)] <- FALSE
    return(check.vector)
}

See:
?all.equal

Hth,
Adrian

On Tue, Apr 5, 2016 at 2:34 PM, Rainer Johannes <Johannes.Rainer at
eurac.edu<mailto:Johannes.Rainer at eurac.edu>> wrote:
Dear All,

I have the following problem:

I have a function in which I check if the difference between values is smaller
or equal to a certain threshold. I however realized that I might get there some
unexpected results:
> abs(1 - 0.95) >= 0.05[1] TRUE
## So that?s fine, but:> abs(1 - 0.95) <= 0.05[1] FALSE

Apparently, abs(1 - 0.95) is not equal to 0.05, which I find however quite
disturbing.

Along these lines:> abs(0.95 - 1) > 0.05
[1] TRUE> abs(0.95 - 1) < 0.05[1] FALSE

I guess that has to do with the floating point representation of the data?

Is there something I miss or is there any solution to this?
Thanks for any help!

cheers, jo

I tried this on different R-version (including 3.2.3 and 3.3.0 alpha); The
R-version I used for the code above is:
> sessionInfo()R version 3.0.2 (2013-09-25)
Platform: x86_64-unknown-linux-gnu (64-bit)

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
 [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
 [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
 [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
 [9] LC_ADDRESS=C               LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base
______________________________________________
R-help at r-project.org<mailto:R-help at r-project.org> mailing list -- To
UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html>
and provide commented, minimal, self-contained, reproducible code.

--
Adrian Dusa
University of Bucharest
Romanian Social Data Archive
Soseaua Panduri nr.90
050663 Bucharest sector 5
Romania

	[[alternative HTML version deleted]]

Thierry Onkelinx

2016-Apr-05 14:07 UTC

head link

[R] Problem with <= (less than or equal): not giving the expected result

You could use something like this

x <- abs(0.95 - 1)
treshold <- 0.05
x < treshold | abs(x - treshold) < 1e-6


ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and
Forest
team Biometrie & Kwaliteitszorg / team Biometrics & Quality Assurance
Kliniekstraat 25
1070 Anderlecht
Belgium

To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to say
what the experiment died of. ~ Sir Ronald Aylmer Fisher
The plural of anecdote is not data. ~ Roger Brinner
The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of data.
~ John Tukey

2016-04-05 14:46 GMT+02:00 Rainer Johannes <Johannes.Rainer at eurac.edu>:
> Thanks Adrian and Thierry (from the previous answer).
>
> I was aware of the all.equal function, but there is nothing similar for
<> (e.g. all.smallerEqual)?
>
> cheers, jo
>
> On 05 Apr 2016, at 14:31, Adrian Du?a <dusa.adrian at
unibuc.ro<mailto:
> dusa.adrian at unibuc.ro>> wrote:
>
> Yes, that does have to do with floating point representation.
> I use this function for these types of comparisons (works with values as
> well as with vectors):
>
> check.equal <- function(x, y) {
>     check.vector <- as.logical(unlist(lapply(x, all.equal, y)))
>     check.vector[is.na<http://is.na/>(check.vector)] <- FALSE
>     return(check.vector)
> }
>
> See:
> ?all.equal
>
> Hth,
> Adrian
>
> On Tue, Apr 5, 2016 at 2:34 PM, Rainer Johannes <Johannes.Rainer at
eurac.edu
> <mailto:Johannes.Rainer at eurac.edu>> wrote:
> Dear All,
>
> I have the following problem:
>
> I have a function in which I check if the difference between values is
> smaller or equal to a certain threshold. I however realized that I might
> get there some unexpected results:
>
> > abs(1 - 0.95) >= 0.05
> [1] TRUE
> ## So that?s fine, but:
> > abs(1 - 0.95) <= 0.05
> [1] FALSE
>
> Apparently, abs(1 - 0.95) is not equal to 0.05, which I find however quite
> disturbing.
>
> Along these lines:
> > abs(0.95 - 1) > 0.05
> [1] TRUE
> > abs(0.95 - 1) < 0.05
> [1] FALSE
>
> I guess that has to do with the floating point representation of the data?
>
> Is there something I miss or is there any solution to this?
> Thanks for any help!
>
> cheers, jo
>
>
>
> I tried this on different R-version (including 3.2.3 and 3.3.0 alpha); The
> R-version I used for the code above is:
>
> > sessionInfo()
> R version 3.0.2 (2013-09-25)
> Platform: x86_64-unknown-linux-gnu (64-bit)
>
> locale:
>  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
>  [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
>  [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
>  [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
>  [9] LC_ADDRESS=C               LC_TELEPHONE=C
> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
> ______________________________________________
> R-help at r-project.org<mailto:R-help at r-project.org> mailing list
-- To
> UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html<
> http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>
>
>
> --
> Adrian Dusa
> University of Bucharest
> Romanian Social Data Archive
> Soseaua Panduri nr.90
> 050663 Bucharest sector 5
> Romania
>
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
	[[alternative HTML version deleted]]

Rainer Johannes

2016-Apr-05 14:32 UTC

head link

[R] Problem with <= (less than or equal): not giving the expected result

Thanks!

On 05 Apr 2016, at 16:07, Thierry Onkelinx <thierry.onkelinx at
inbo.be<mailto:thierry.onkelinx at inbo.be>> wrote:

You could use something like this

x <- abs(0.95 - 1)
treshold <- 0.05
x < treshold | abs(x - treshold) < 1e-6

ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and
Forest
team Biometrie & Kwaliteitszorg / team Biometrics & Quality Assurance
Kliniekstraat 25
1070 Anderlecht
Belgium

To call in the statistician after the experiment is done may be no more than
asking him to perform a post-mortem examination: he may be able to say what the
experiment died of. ~ Sir Ronald Aylmer Fisher
The plural of anecdote is not data. ~ Roger Brinner
The combination of some data and an aching desire for an answer does not ensure
that a reasonable answer can be extracted from a given body of data. ~ John
Tukey

2016-04-05 14:46 GMT+02:00 Rainer Johannes <Johannes.Rainer at
eurac.edu<mailto:Johannes.Rainer at eurac.edu>>:
Thanks Adrian and Thierry (from the previous answer).

I was aware of the all.equal function, but there is nothing similar for <=
(e.g. all.smallerEqual)?

cheers, jo

On 05 Apr 2016, at 14:31, Adrian Du?a <dusa.adrian at
unibuc.ro<mailto:dusa.adrian at unibuc.ro><mailto:dusa.adrian at
unibuc.ro<mailto:dusa.adrian at unibuc.ro>>> wrote:

Yes, that does have to do with floating point representation.
I use this function for these types of comparisons (works with values as well as
with vectors):

check.equal <- function(x, y) {
    check.vector <- as.logical(unlist(lapply(x, all.equal, y)))
    check.vector[is.na<http://is.na/><http://is.na/>(check.vector)]
<- FALSE
    return(check.vector)
}

See:
?all.equal

Hth,
Adrian

On Tue, Apr 5, 2016 at 2:34 PM, Rainer Johannes <Johannes.Rainer at
eurac.edu<mailto:Johannes.Rainer at eurac.edu><mailto:Johannes.Rainer
at eurac.edu<mailto:Johannes.Rainer at eurac.edu>>> wrote:
Dear All,

I have the following problem:

I have a function in which I check if the difference between values is smaller
or equal to a certain threshold. I however realized that I might get there some
unexpected results:
> abs(1 - 0.95) >= 0.05[1] TRUE
## So that?s fine, but:> abs(1 - 0.95) <= 0.05[1] FALSE

Apparently, abs(1 - 0.95) is not equal to 0.05, which I find however quite
disturbing.

Along these lines:> abs(0.95 - 1) > 0.05
[1] TRUE> abs(0.95 - 1) < 0.05[1] FALSE

I guess that has to do with the floating point representation of the data?

Is there something I miss or is there any solution to this?
Thanks for any help!

cheers, jo

I tried this on different R-version (including 3.2.3 and 3.3.0 alpha); The
R-version I used for the code above is:
> sessionInfo()R version 3.0.2 (2013-09-25)
Platform: x86_64-unknown-linux-gnu (64-bit)

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
 [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
 [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
 [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
 [9] LC_ADDRESS=C               LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base
______________________________________________
R-help at r-project.org<mailto:R-help at r-project.org><mailto:R-help
at r-project.org<mailto:R-help at r-project.org>> mailing list -- To
UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html><http://www.r-project.org/posting-guide.html>
and provide commented, minimal, self-contained, reproducible code.

--
Adrian Dusa
University of Bucharest
Romanian Social Data Archive
Soseaua Panduri nr.90
050663 Bucharest sector 5
Romania

        [[alternative HTML version deleted]]

______________________________________________
R-help at r-project.org<mailto:R-help at r-project.org> mailing list -- To
UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html>
and provide commented, minimal, self-contained, reproducible code.

	[[alternative HTML version deleted]]

David Winsemius

2016-Apr-05 14:38 UTC

head link

[R] Problem with <= (less than or equal): not giving the expected result

> On Apr 5, 2016, at 5:46 AM, Rainer Johannes <Johannes.Rainer at
eurac.edu> wrote:
> 
> Thanks Adrian and Thierry (from the previous answer).
> 
> I was aware of the all.equal function, but there is nothing similar for
<= (e.g. all.smallerEqual)?
Perhaps you will gain understanding by looking at this:
> abs(1 - 0.95) - 0.05[1] 4.163336e-17

Perhaps you want to make your own `all.<=`
> '%all.<=%'   <- function (e1,e2){ e1 < e2 | abs(e1-e2)
< .Machine$double.eps^0.5 }
> abs(1 - 0.95) %all.<=% 0.05[1] TRUE


-- 
David.> 
> cheers, jo
> 
> On 05 Apr 2016, at 14:31, Adrian Du?a <dusa.adrian at
unibuc.ro<mailto:dusa.adrian at unibuc.ro>> wrote:
> 
> Yes, that does have to do with floating point representation.
> I use this function for these types of comparisons (works with values as
well as with vectors):
> 
> check.equal <- function(x, y) {
>    check.vector <- as.logical(unlist(lapply(x, all.equal, y)))
>    check.vector[is.na<http://is.na/>(check.vector)] <- FALSE
>    return(check.vector)
> }
> 
> See:
> ?all.equal
> 
> Hth,
> Adrian
> 
> On Tue, Apr 5, 2016 at 2:34 PM, Rainer Johannes <Johannes.Rainer at
eurac.edu<mailto:Johannes.Rainer at eurac.edu>> wrote:
> Dear All,
> 
> I have the following problem:
> 
> I have a function in which I check if the difference between values is
smaller or equal to a certain threshold. I however realized that I might get
there some unexpected results:
> 
>> abs(1 - 0.95) >= 0.05
> [1] TRUE
> ## So that?s fine, but:
>> abs(1 - 0.95) <= 0.05
> [1] FALSE
> 
> Apparently, abs(1 - 0.95) is not equal to 0.05, which I find however quite
disturbing.
> 
> Along these lines:
>> abs(0.95 - 1) > 0.05
> [1] TRUE
>> abs(0.95 - 1) < 0.05
> [1] FALSE
> 
> I guess that has to do with the floating point representation of the data?
> 
> Is there something I miss or is there any solution to this?
> Thanks for any help!
> 
> cheers, jo
> 
> 
> 
> I tried this on different R-version (including 3.2.3 and 3.3.0 alpha); The
R-version I used for the code above is:
> 
>> sessionInfo()
> R version 3.0.2 (2013-09-25)
> Platform: x86_64-unknown-linux-gnu (64-bit)
> 
> locale:
> [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
> [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
> [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
> [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
> [9] LC_ADDRESS=C               LC_TELEPHONE=C
> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
> 
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
> ______________________________________________
> R-help at r-project.org<mailto:R-help at r-project.org> mailing list
-- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
> 
> 
> 
> --
> Adrian Dusa
> University of Bucharest
> Romanian Social Data Archive
> Soseaua Panduri nr.90
> 050663 Bucharest sector 5
> Romania
> 
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
David Winsemius
Alameda, CA, USA

Apparently Analagous Threads

Search for more seemingly similar threads

R help - Apr 2016 - Problem with <= (less than or equal): not giving the expected result

[R] Problem with <= (less than or equal): not giving the expected result

[R] Problem with <= (less than or equal): not giving the expected result

[R] Problem with <= (less than or equal): not giving the expected result

[R] Problem with <= (less than or equal): not giving the expected result

Apparently Analagous Threads