Akhilesh Singh
2016-Apr-14 20:14 UTC
[R] Bug in by() function which works for some FUN argument and does not work for others
Dear Sirs, I am Professor at Indira Gandhi Krishi Vishwavidyalaya, Raipur, Chhattisgarh, India. While taking classes, I found the *by() *function producing following error when I use FUN=mean or median and some other functions, however, FUN=summary works. Given below is the output of the example I used on a built-in dataset "mtcars", along with error message reproduced herewith:> by(data=mtcars, INDICES=list(mtcars$am), FUN=mean): 0 [1] NA ------------------------------------------------------------ : 1 [1] NA Warning messages: 1: In mean.default(data[x, , drop = FALSE], ...) : argument is not numeric or logical: returning NA 2: In mean.default(data[x, , drop = FALSE], ...) : argument is not numeric or logical: returning NA However, the same by() function works for FUN=summary, given below is the output:> by(data=mtcars, INDICES=list(mtcars$am), FUN=summary): 0 mpg cyl disp hp Min. :10.40 Min. :4.000 Min. :120.1 Min. : 62.0 1st Qu.:14.95 1st Qu.:6.000 1st Qu.:196.3 1st Qu.:116.5 Median :17.30 Median :8.000 Median :275.8 Median :175.0 Mean :17.15 Mean :6.947 Mean :290.4 Mean :160.3 3rd Qu.:19.20 3rd Qu.:8.000 3rd Qu.:360.0 3rd Qu.:192.5 Max. :24.40 Max. :8.000 Max. :472.0 Max. :245.0 drat wt qsec vs am Min. :2.760 Min. :2.465 Min. :15.41 Min. :0.0000 Min. :0 1st Qu.:3.070 1st Qu.:3.438 1st Qu.:17.18 1st Qu.:0.0000 1st Qu.:0 Median :3.150 Median :3.520 Median :17.82 Median :0.0000 Median :0 Mean :3.286 Mean :3.769 Mean :18.18 Mean :0.3684 Mean :0 3rd Qu.:3.695 3rd Qu.:3.842 3rd Qu.:19.17 3rd Qu.:1.0000 3rd Qu.:0 Max. :3.920 Max. :5.424 Max. :22.90 Max. :1.0000 Max. :0 gear carb Min. :3.000 Min. :1.000 1st Qu.:3.000 1st Qu.:2.000 Median :3.000 Median :3.000 Mean :3.211 Mean :2.737 3rd Qu.:3.000 3rd Qu.:4.000 Max. :4.000 Max. :4.000 ------------------------------------------------------------ : 1 mpg cyl disp hp drat Min. :15.00 Min. :4.000 Min. : 71.1 Min. : 52.0 Min. :3.54 1st Qu.:21.00 1st Qu.:4.000 1st Qu.: 79.0 1st Qu.: 66.0 1st Qu.:3.85 Median :22.80 Median :4.000 Median :120.3 Median :109.0 Median :4.08 Mean :24.39 Mean :5.077 Mean :143.5 Mean :126.8 Mean :4.05 3rd Qu.:30.40 3rd Qu.:6.000 3rd Qu.:160.0 3rd Qu.:113.0 3rd Qu.:4.22 Max. :33.90 Max. :8.000 Max. :351.0 Max. :335.0 Max. :4.93 wt qsec vs am gear Min. :1.513 Min. :14.50 Min. :0.0000 Min. :1 Min. :4.000 1st Qu.:1.935 1st Qu.:16.46 1st Qu.:0.0000 1st Qu.:1 1st Qu.:4.000 Median :2.320 Median :17.02 Median :1.0000 Median :1 Median :4.000 Mean :2.411 Mean :17.36 Mean :0.5385 Mean :1 Mean :4.385 3rd Qu.:2.780 3rd Qu.:18.61 3rd Qu.:1.0000 3rd Qu.:1 3rd Qu.:5.000 Max. :3.570 Max. :19.90 Max. :1.0000 Max. :1 Max. :5.000 carb Min. :1.000 1st Qu.:1.000 Median :2.000 Mean :2.923 3rd Qu.:4.000 Max. :8.000>I am using the latest version of *R-3.2.4 on Windows*, however, this error is being generated in the previous version too, Hope this reporting will get serious attention in debugging. With best regards, Dr. A.K. Singh Head, Department of Agril. Statistics Indira Gandhi Krishi Vishwavidyalaya, Raipur Chhattisgarh, India, PIN-492012 Mobile: +919752620740 Email: akhileshsingh.igkv at gmail.com [[alternative HTML version deleted]]
Adrian Dușa
2016-Apr-14 21:36 UTC
[R] Bug in by() function which works for some FUN argument and does not work for others
I think you are not using the best function for what your intentions are. Try:> by(data=mtcars, INDICES=list(as.factor(mtcars$am)), FUN=colMeans): 0 mpg cyl disp hp drat wt qsec vs 17.1473684 6.9473684 290.3789474 160.2631579 3.2863158 3.7688947 18.1831579 0.3684211 am gear carb 0.0000000 3.2105263 2.7368421 --------------------------------------------------------------------------- : 1 mpg cyl disp hp drat wt qsec vs 24.3923077 5.0769231 143.5307692 126.8461538 4.0500000 2.4110000 17.3600000 0.5384615 am gear carb 1.0000000 4.3846154 2.9230769 See the difference between colMeans() and mean() in their respective help files. Hth, Adrian On Thu, Apr 14, 2016 at 11:14 PM, Akhilesh Singh < akhileshsingh.igkv at gmail.com> wrote:> Dear Sirs, > > I am Professor at Indira Gandhi Krishi Vishwavidyalaya, Raipur, > Chhattisgarh, India. > > While taking classes, I found the *by() *function producing following error > when I use FUN=mean or median and some other functions, however, > FUN=summary works. > > Given below is the output of the example I used on a built-in dataset > "mtcars", along with error message reproduced herewith: > > > by(data=mtcars, INDICES=list(mtcars$am), FUN=mean) > : 0 > [1] NA > ------------------------------------------------------------ > : 1 > [1] NA > Warning messages: > 1: In mean.default(data[x, , drop = FALSE], ...) : > argument is not numeric or logical: returning NA > 2: In mean.default(data[x, , drop = FALSE], ...) : > argument is not numeric or logical: returning NA > > However, the same by() function works for FUN=summary, given below is the > output: > > > by(data=mtcars, INDICES=list(mtcars$am), FUN=summary) > : 0 > mpg cyl disp hp > Min. :10.40 Min. :4.000 Min. :120.1 Min. : 62.0 > 1st Qu.:14.95 1st Qu.:6.000 1st Qu.:196.3 1st Qu.:116.5 > Median :17.30 Median :8.000 Median :275.8 Median :175.0 > Mean :17.15 Mean :6.947 Mean :290.4 Mean :160.3 > 3rd Qu.:19.20 3rd Qu.:8.000 3rd Qu.:360.0 3rd Qu.:192.5 > Max. :24.40 Max. :8.000 Max. :472.0 Max. :245.0 > drat wt qsec vs am > > Min. :2.760 Min. :2.465 Min. :15.41 Min. :0.0000 Min. :0 > > 1st Qu.:3.070 1st Qu.:3.438 1st Qu.:17.18 1st Qu.:0.0000 1st Qu.:0 > > Median :3.150 Median :3.520 Median :17.82 Median :0.0000 Median :0 > > Mean :3.286 Mean :3.769 Mean :18.18 Mean :0.3684 Mean :0 > > 3rd Qu.:3.695 3rd Qu.:3.842 3rd Qu.:19.17 3rd Qu.:1.0000 3rd Qu.:0 > > Max. :3.920 Max. :5.424 Max. :22.90 Max. :1.0000 Max. :0 > > gear carb > Min. :3.000 Min. :1.000 > 1st Qu.:3.000 1st Qu.:2.000 > Median :3.000 Median :3.000 > Mean :3.211 Mean :2.737 > 3rd Qu.:3.000 3rd Qu.:4.000 > Max. :4.000 Max. :4.000 > ------------------------------------------------------------ > : 1 > mpg cyl disp hp drat > > Min. :15.00 Min. :4.000 Min. : 71.1 Min. : 52.0 Min. > :3.54 > 1st Qu.:21.00 1st Qu.:4.000 1st Qu.: 79.0 1st Qu.: 66.0 1st > Qu.:3.85 > Median :22.80 Median :4.000 Median :120.3 Median :109.0 Median > :4.08 > Mean :24.39 Mean :5.077 Mean :143.5 Mean :126.8 Mean > :4.05 > 3rd Qu.:30.40 3rd Qu.:6.000 3rd Qu.:160.0 3rd Qu.:113.0 3rd > Qu.:4.22 > Max. :33.90 Max. :8.000 Max. :351.0 Max. :335.0 Max. > :4.93 > wt qsec vs am gear > > Min. :1.513 Min. :14.50 Min. :0.0000 Min. :1 Min. :4.000 > > 1st Qu.:1.935 1st Qu.:16.46 1st Qu.:0.0000 1st Qu.:1 1st Qu.:4.000 > > Median :2.320 Median :17.02 Median :1.0000 Median :1 Median :4.000 > > Mean :2.411 Mean :17.36 Mean :0.5385 Mean :1 Mean :4.385 > > 3rd Qu.:2.780 3rd Qu.:18.61 3rd Qu.:1.0000 3rd Qu.:1 3rd Qu.:5.000 > > Max. :3.570 Max. :19.90 Max. :1.0000 Max. :1 Max. :5.000 > > carb > Min. :1.000 > 1st Qu.:1.000 > Median :2.000 > Mean :2.923 > 3rd Qu.:4.000 > Max. :8.000 > > > > I am using the latest version of *R-3.2.4 on Windows*, however, this error > is being generated in the previous version too, > > Hope this reporting will get serious attention in debugging. > > With best regards, > > Dr. A.K. Singh > Head, Department of Agril. Statistics > Indira Gandhi Krishi Vishwavidyalaya, Raipur > Chhattisgarh, India, PIN-492012 > Mobile: +919752620740 > Email: akhileshsingh.igkv at gmail.com > > [[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. >-- Adrian Dusa University of Bucharest Romanian Social Data Archive Soseaua Panduri nr.90 050663 Bucharest sector 5 Romania [[alternative HTML version deleted]]
Bert Gunter
2016-Apr-14 22:45 UTC
[R] Bug in by() function which works for some FUN argument and does not work for others
You're right, but I think this fails to pinpoint the error. The problem is that FUN's argument is "applied to (usually data-frame) subsets of data," and the OP has used FUN = mean, which takes a vector (+ a few other classes), not a data frame, as argument. See ?mean Morals: 1. It is rather presumptuous to think that long used, well-tested, core R functionality like by() have bugs; a (new?) user's first thought should be to assume it is HIS error, not R's. 2. DO read the Help docs carefully. They are often terse, but usually they mean what they (appear to) say. Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Thu, Apr 14, 2016 at 2:36 PM, Adrian Du?a <dusa.adrian at unibuc.ro> wrote:> I think you are not using the best function for what your intentions are. > Try: > >> by(data=mtcars, INDICES=list(as.factor(mtcars$am)), FUN=colMeans) > : 0 > mpg cyl disp hp drat wt > qsec vs > 17.1473684 6.9473684 290.3789474 160.2631579 3.2863158 3.7688947 > 18.1831579 0.3684211 > am gear carb > 0.0000000 3.2105263 2.7368421 > --------------------------------------------------------------------------- > : 1 > mpg cyl disp hp drat wt > qsec vs > 24.3923077 5.0769231 143.5307692 126.8461538 4.0500000 2.4110000 > 17.3600000 0.5384615 > am gear carb > 1.0000000 4.3846154 2.9230769 > > See the difference between colMeans() and mean() in their respective help > files. > Hth, > Adrian > > On Thu, Apr 14, 2016 at 11:14 PM, Akhilesh Singh < > akhileshsingh.igkv at gmail.com> wrote: > >> Dear Sirs, >> >> I am Professor at Indira Gandhi Krishi Vishwavidyalaya, Raipur, >> Chhattisgarh, India. >> >> While taking classes, I found the *by() *function producing following error >> when I use FUN=mean or median and some other functions, however, >> FUN=summary works. >> >> Given below is the output of the example I used on a built-in dataset >> "mtcars", along with error message reproduced herewith: >> >> > by(data=mtcars, INDICES=list(mtcars$am), FUN=mean) >> : 0 >> [1] NA >> ------------------------------------------------------------ >> : 1 >> [1] NA >> Warning messages: >> 1: In mean.default(data[x, , drop = FALSE], ...) : >> argument is not numeric or logical: returning NA >> 2: In mean.default(data[x, , drop = FALSE], ...) : >> argument is not numeric or logical: returning NA >> >> However, the same by() function works for FUN=summary, given below is the >> output: >> >> > by(data=mtcars, INDICES=list(mtcars$am), FUN=summary) >> : 0 >> mpg cyl disp hp >> Min. :10.40 Min. :4.000 Min. :120.1 Min. : 62.0 >> 1st Qu.:14.95 1st Qu.:6.000 1st Qu.:196.3 1st Qu.:116.5 >> Median :17.30 Median :8.000 Median :275.8 Median :175.0 >> Mean :17.15 Mean :6.947 Mean :290.4 Mean :160.3 >> 3rd Qu.:19.20 3rd Qu.:8.000 3rd Qu.:360.0 3rd Qu.:192.5 >> Max. :24.40 Max. :8.000 Max. :472.0 Max. :245.0 >> drat wt qsec vs am >> >> Min. :2.760 Min. :2.465 Min. :15.41 Min. :0.0000 Min. :0 >> >> 1st Qu.:3.070 1st Qu.:3.438 1st Qu.:17.18 1st Qu.:0.0000 1st Qu.:0 >> >> Median :3.150 Median :3.520 Median :17.82 Median :0.0000 Median :0 >> >> Mean :3.286 Mean :3.769 Mean :18.18 Mean :0.3684 Mean :0 >> >> 3rd Qu.:3.695 3rd Qu.:3.842 3rd Qu.:19.17 3rd Qu.:1.0000 3rd Qu.:0 >> >> Max. :3.920 Max. :5.424 Max. :22.90 Max. :1.0000 Max. :0 >> >> gear carb >> Min. :3.000 Min. :1.000 >> 1st Qu.:3.000 1st Qu.:2.000 >> Median :3.000 Median :3.000 >> Mean :3.211 Mean :2.737 >> 3rd Qu.:3.000 3rd Qu.:4.000 >> Max. :4.000 Max. :4.000 >> ------------------------------------------------------------ >> : 1 >> mpg cyl disp hp drat >> >> Min. :15.00 Min. :4.000 Min. : 71.1 Min. : 52.0 Min. >> :3.54 >> 1st Qu.:21.00 1st Qu.:4.000 1st Qu.: 79.0 1st Qu.: 66.0 1st >> Qu.:3.85 >> Median :22.80 Median :4.000 Median :120.3 Median :109.0 Median >> :4.08 >> Mean :24.39 Mean :5.077 Mean :143.5 Mean :126.8 Mean >> :4.05 >> 3rd Qu.:30.40 3rd Qu.:6.000 3rd Qu.:160.0 3rd Qu.:113.0 3rd >> Qu.:4.22 >> Max. :33.90 Max. :8.000 Max. :351.0 Max. :335.0 Max. >> :4.93 >> wt qsec vs am gear >> >> Min. :1.513 Min. :14.50 Min. :0.0000 Min. :1 Min. :4.000 >> >> 1st Qu.:1.935 1st Qu.:16.46 1st Qu.:0.0000 1st Qu.:1 1st Qu.:4.000 >> >> Median :2.320 Median :17.02 Median :1.0000 Median :1 Median :4.000 >> >> Mean :2.411 Mean :17.36 Mean :0.5385 Mean :1 Mean :4.385 >> >> 3rd Qu.:2.780 3rd Qu.:18.61 3rd Qu.:1.0000 3rd Qu.:1 3rd Qu.:5.000 >> >> Max. :3.570 Max. :19.90 Max. :1.0000 Max. :1 Max. :5.000 >> >> carb >> Min. :1.000 >> 1st Qu.:1.000 >> Median :2.000 >> Mean :2.923 >> 3rd Qu.:4.000 >> Max. :8.000 >> > >> >> I am using the latest version of *R-3.2.4 on Windows*, however, this error >> is being generated in the previous version too, >> >> Hope this reporting will get serious attention in debugging. >> >> With best regards, >> >> Dr. A.K. Singh >> Head, Department of Agril. Statistics >> Indira Gandhi Krishi Vishwavidyalaya, Raipur >> Chhattisgarh, India, PIN-492012 >> Mobile: +919752620740 >> Email: akhileshsingh.igkv at gmail.com >> >> [[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. >> > > > > -- > 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.
Jim Lemon
2016-Apr-14 23:08 UTC
[R] Bug in by() function which works for some FUN argument and does not work for others
Hi Dr Singh, The object mtcars is a data frame and the mean is not defined for a data frame. If you try it on a component of the data frame for which mean is defined: by(mtcars$mpg,mtcars$am,mean) mtcars$am: 0 [1] 17.14737 ------------------------------------------------------------ mtcars$am: 1 [1] 24.39231 Jim On Fri, Apr 15, 2016 at 6:14 AM, Akhilesh Singh <akhileshsingh.igkv at gmail.com> wrote:> Dear Sirs, > > I am Professor at Indira Gandhi Krishi Vishwavidyalaya, Raipur, > Chhattisgarh, India. > > While taking classes, I found the *by() *function producing following error > when I use FUN=mean or median and some other functions, however, > FUN=summary works. > > Given below is the output of the example I used on a built-in dataset > "mtcars", along with error message reproduced herewith: > >> by(data=mtcars, INDICES=list(mtcars$am), FUN=mean) > : 0 > [1] NA > ------------------------------------------------------------ > : 1 > [1] NA > Warning messages: > 1: In mean.default(data[x, , drop = FALSE], ...) : > argument is not numeric or logical: returning NA > 2: In mean.default(data[x, , drop = FALSE], ...) : > argument is not numeric or logical: returning NA > > However, the same by() function works for FUN=summary, given below is the > output: > >> by(data=mtcars, INDICES=list(mtcars$am), FUN=summary) > : 0 > mpg cyl disp hp > Min. :10.40 Min. :4.000 Min. :120.1 Min. : 62.0 > 1st Qu.:14.95 1st Qu.:6.000 1st Qu.:196.3 1st Qu.:116.5 > Median :17.30 Median :8.000 Median :275.8 Median :175.0 > Mean :17.15 Mean :6.947 Mean :290.4 Mean :160.3 > 3rd Qu.:19.20 3rd Qu.:8.000 3rd Qu.:360.0 3rd Qu.:192.5 > Max. :24.40 Max. :8.000 Max. :472.0 Max. :245.0 > drat wt qsec vs am > > Min. :2.760 Min. :2.465 Min. :15.41 Min. :0.0000 Min. :0 > > 1st Qu.:3.070 1st Qu.:3.438 1st Qu.:17.18 1st Qu.:0.0000 1st Qu.:0 > > Median :3.150 Median :3.520 Median :17.82 Median :0.0000 Median :0 > > Mean :3.286 Mean :3.769 Mean :18.18 Mean :0.3684 Mean :0 > > 3rd Qu.:3.695 3rd Qu.:3.842 3rd Qu.:19.17 3rd Qu.:1.0000 3rd Qu.:0 > > Max. :3.920 Max. :5.424 Max. :22.90 Max. :1.0000 Max. :0 > > gear carb > Min. :3.000 Min. :1.000 > 1st Qu.:3.000 1st Qu.:2.000 > Median :3.000 Median :3.000 > Mean :3.211 Mean :2.737 > 3rd Qu.:3.000 3rd Qu.:4.000 > Max. :4.000 Max. :4.000 > ------------------------------------------------------------ > : 1 > mpg cyl disp hp drat > > Min. :15.00 Min. :4.000 Min. : 71.1 Min. : 52.0 Min. > :3.54 > 1st Qu.:21.00 1st Qu.:4.000 1st Qu.: 79.0 1st Qu.: 66.0 1st > Qu.:3.85 > Median :22.80 Median :4.000 Median :120.3 Median :109.0 Median > :4.08 > Mean :24.39 Mean :5.077 Mean :143.5 Mean :126.8 Mean > :4.05 > 3rd Qu.:30.40 3rd Qu.:6.000 3rd Qu.:160.0 3rd Qu.:113.0 3rd > Qu.:4.22 > Max. :33.90 Max. :8.000 Max. :351.0 Max. :335.0 Max. > :4.93 > wt qsec vs am gear > > Min. :1.513 Min. :14.50 Min. :0.0000 Min. :1 Min. :4.000 > > 1st Qu.:1.935 1st Qu.:16.46 1st Qu.:0.0000 1st Qu.:1 1st Qu.:4.000 > > Median :2.320 Median :17.02 Median :1.0000 Median :1 Median :4.000 > > Mean :2.411 Mean :17.36 Mean :0.5385 Mean :1 Mean :4.385 > > 3rd Qu.:2.780 3rd Qu.:18.61 3rd Qu.:1.0000 3rd Qu.:1 3rd Qu.:5.000 > > Max. :3.570 Max. :19.90 Max. :1.0000 Max. :1 Max. :5.000 > > carb > Min. :1.000 > 1st Qu.:1.000 > Median :2.000 > Mean :2.923 > 3rd Qu.:4.000 > Max. :8.000 >> > > I am using the latest version of *R-3.2.4 on Windows*, however, this error > is being generated in the previous version too, > > Hope this reporting will get serious attention in debugging. > > With best regards, > > Dr. A.K. Singh > Head, Department of Agril. Statistics > Indira Gandhi Krishi Vishwavidyalaya, Raipur > Chhattisgarh, India, PIN-492012 > Mobile: +919752620740 > Email: akhileshsingh.igkv at gmail.com > > [[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.
Akhilesh Singh
2016-Apr-15 08:16 UTC
[R] Bug in by() function which works for some FUN argument and does not work for others
Dear All,
Thanks for your help. However, I would like to draw your attention to the
following:
Actually, I was replicating the Example 2.3, using the dataset
"brainsize.txt" given in Section 2.3.3 ("Summarize by
group") at page 55,
of a famous book "R by Example" written by "Jim Albert and Maria
Rizzo"
published in Springers (2012) in a Use R! Series. The output of the by()
function printed in the book is being reproduced below for information to
all:
> by(data=brain[, -1], INDICES=brain$Gender, FUN=mean, na.rm=TRUE)
brain$Gender: Female
FSIQ VIQ PIQ Weight Height MRI_Count
111.900 109.450 110.450 137.200 65.765 862654.600
------------------------------------------------------------
brain$Gender: Male
FSIQ VIQ PIQ Weight Height MRI_Count
115.00000 115.25000 111.60000 166.44444 71.43158 954855.40000
I do not know how could the writers of the book have produced the above
results by by() function. But, when I could not reproduce these results,
then I thought that probably, this could possibly be due to some missing
values NA's in Weight and Height variables. Then I tried the above code for
the "mtcars" dataset for INDICES=mtcars$am. When I found the same
results
here too, then I reported the case in "r-help at R-project.org".
With best regards,
Dr. A.K. Singh
Head, Department of Agril. Statistics
Indira Gandhi Krishi Vishwavidyalaya, Raipur
Chhattisgarh, India, PIN-492012
Mobile: +919752620740
Email: akhileshsingh.igkv at gmail.com
On Fri, Apr 15, 2016 at 3:06 AM, Adrian Du?a <dusa.adrian at unibuc.ro>
wrote:
> I think you are not using the best function for what your intentions are.
> Try:
>
> > by(data=mtcars, INDICES=list(as.factor(mtcars$am)), FUN=colMeans)
> : 0
> mpg cyl disp hp drat wt
> qsec vs
> 17.1473684 6.9473684 290.3789474 160.2631579 3.2863158 3.7688947
> 18.1831579 0.3684211
> am gear carb
> 0.0000000 3.2105263 2.7368421
>
> ---------------------------------------------------------------------------
> : 1
> mpg cyl disp hp drat wt
> qsec vs
> 24.3923077 5.0769231 143.5307692 126.8461538 4.0500000 2.4110000
> 17.3600000 0.5384615
> am gear carb
> 1.0000000 4.3846154 2.9230769
>
> See the difference between colMeans() and mean() in their respective help
> files.
> Hth,
> Adrian
>
> On Thu, Apr 14, 2016 at 11:14 PM, Akhilesh Singh <
> akhileshsingh.igkv at gmail.com> wrote:
>
>> Dear Sirs,
>>
>> I am Professor at Indira Gandhi Krishi Vishwavidyalaya, Raipur,
>> Chhattisgarh, India.
>>
>> While taking classes, I found the *by() *function producing following
>> error
>>
>> when I use FUN=mean or median and some other functions, however,
>> FUN=summary works.
>>
>> Given below is the output of the example I used on a built-in dataset
>> "mtcars", along with error message reproduced herewith:
>>
>> > by(data=mtcars, INDICES=list(mtcars$am), FUN=mean)
>> : 0
>> [1] NA
>> ------------------------------------------------------------
>> : 1
>> [1] NA
>> Warning messages:
>> 1: In mean.default(data[x, , drop = FALSE], ...) :
>> argument is not numeric or logical: returning NA
>> 2: In mean.default(data[x, , drop = FALSE], ...) :
>> argument is not numeric or logical: returning NA
>>
>> However, the same by() function works for FUN=summary, given below is
the
>> output:
>>
>> > by(data=mtcars, INDICES=list(mtcars$am), FUN=summary)
>> : 0
>> mpg cyl disp hp
>> Min. :10.40 Min. :4.000 Min. :120.1 Min. : 62.0
>> 1st Qu.:14.95 1st Qu.:6.000 1st Qu.:196.3 1st Qu.:116.5
>> Median :17.30 Median :8.000 Median :275.8 Median :175.0
>> Mean :17.15 Mean :6.947 Mean :290.4 Mean :160.3
>> 3rd Qu.:19.20 3rd Qu.:8.000 3rd Qu.:360.0 3rd Qu.:192.5
>> Max. :24.40 Max. :8.000 Max. :472.0 Max. :245.0
>> drat wt qsec vs
am
>>
>> Min. :2.760 Min. :2.465 Min. :15.41 Min. :0.0000 Min.
>> :0
>>
>> 1st Qu.:3.070 1st Qu.:3.438 1st Qu.:17.18 1st Qu.:0.0000 1st
>> Qu.:0
>>
>> Median :3.150 Median :3.520 Median :17.82 Median :0.0000
Median
>> :0
>>
>> Mean :3.286 Mean :3.769 Mean :18.18 Mean :0.3684 Mean
>> :0
>>
>> 3rd Qu.:3.695 3rd Qu.:3.842 3rd Qu.:19.17 3rd Qu.:1.0000 3rd
>> Qu.:0
>>
>> Max. :3.920 Max. :5.424 Max. :22.90 Max. :1.0000 Max.
>> :0
>>
>> gear carb
>> Min. :3.000 Min. :1.000
>> 1st Qu.:3.000 1st Qu.:2.000
>> Median :3.000 Median :3.000
>> Mean :3.211 Mean :2.737
>> 3rd Qu.:3.000 3rd Qu.:4.000
>> Max. :4.000 Max. :4.000
>> ------------------------------------------------------------
>> : 1
>> mpg cyl disp hp
drat
>>
>> Min. :15.00 Min. :4.000 Min. : 71.1 Min. : 52.0 Min.
>> :3.54
>> 1st Qu.:21.00 1st Qu.:4.000 1st Qu.: 79.0 1st Qu.: 66.0 1st
>> Qu.:3.85
>> Median :22.80 Median :4.000 Median :120.3 Median :109.0 Median
>> :4.08
>> Mean :24.39 Mean :5.077 Mean :143.5 Mean :126.8 Mean
>> :4.05
>> 3rd Qu.:30.40 3rd Qu.:6.000 3rd Qu.:160.0 3rd Qu.:113.0 3rd
>> Qu.:4.22
>> Max. :33.90 Max. :8.000 Max. :351.0 Max. :335.0 Max.
>> :4.93
>> wt qsec vs am gear
>>
>> Min. :1.513 Min. :14.50 Min. :0.0000 Min. :1 Min.
>> :4.000
>>
>> 1st Qu.:1.935 1st Qu.:16.46 1st Qu.:0.0000 1st Qu.:1 1st
>> Qu.:4.000
>>
>> Median :2.320 Median :17.02 Median :1.0000 Median :1 Median
>> :4.000
>>
>> Mean :2.411 Mean :17.36 Mean :0.5385 Mean :1 Mean
>> :4.385
>>
>> 3rd Qu.:2.780 3rd Qu.:18.61 3rd Qu.:1.0000 3rd Qu.:1 3rd
>> Qu.:5.000
>>
>> Max. :3.570 Max. :19.90 Max. :1.0000 Max. :1 Max.
>> :5.000
>>
>> carb
>> Min. :1.000
>> 1st Qu.:1.000
>> Median :2.000
>> Mean :2.923
>> 3rd Qu.:4.000
>> Max. :8.000
>> >
>>
>> I am using the latest version of *R-3.2.4 on Windows*, however, this
error
>> is being generated in the previous version too,
>>
>> Hope this reporting will get serious attention in debugging.
>>
>> With best regards,
>>
>> Dr. A.K. Singh
>> Head, Department of Agril. Statistics
>> Indira Gandhi Krishi Vishwavidyalaya, Raipur
>> Chhattisgarh, India, PIN-492012
>> Mobile: +919752620740
>> Email: akhileshsingh.igkv at gmail.com
>>
>> [[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.
>>
>
>
>
> --
> Adrian Dusa
> University of Bucharest
> Romanian Social Data Archive
> Soseaua Panduri nr.90
> 050663 Bucharest sector 5
> Romania
>
[[alternative HTML version deleted]]
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