Re: [R] Factor levels in training set
Hi Elahe I get slightly different error when using scale to nonnumeric data so I am not sure if you use the scale function from base package. > scale(raman[1:20,]) Error in colMeans(x, na.rm = TRUE) : 'x' must be numeric Anyway, how do you expect scaling shall be done when you have nonumeric variable. What shall be the output of scale(iris$Species) The only workaround is either to scale only numeric variables from your data and add nonnumeric in folowing step or to change all factor variable to numeric before scaling (which I would not recommend). If your data are supposed to be numeric you can check if they really are by str(df) Cheers Petr > -Original Message- > From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of ch.elahe > via R-help > Sent: Tuesday, June 14, 2016 5:29 PM > To: R-help Mailing List <r-help@r-project.org> > Subject: [R] Factor levels in training set > > > Hi all, > I want to use Supervised Self organizing Maps from Kohonen package for my > data. I need to divide my df into training set and test set, but a part of my > df > contains column with factor levels and I don't know how to bring them into > my training set. Currently I use the following command for my training set: > > dt=sort(sample(nrow(df),nrow(df)*.7)) > training=m[dt,] > till here I get no error but in the next step which I need to bring my > training > set in a matrix I face this error: > > scale(df[training,]) > error: 'x' should be numeric > Does anyone know how should I include column with factor levels in my df so > that I don't get this error? > Thanks for any help, > Elahe > > __ > R-help@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. Tento e-mail a jakékoliv k němu připojené dokumenty jsou důvěrné a jsou určeny pouze jeho adresátům. Jestliže jste obdržel(a) tento e-mail omylem, informujte laskavě neprodleně jeho odesílatele. Obsah tohoto emailu i s přílohami a jeho kopie vymažte ze svého systému. Nejste-li zamýšleným adresátem tohoto emailu, nejste oprávněni tento email jakkoliv užívat, rozšiřovat, kopírovat či zveřejňovat. Odesílatel e-mailu neodpovídá za eventuální škodu způsobenou modifikacemi či zpožděním přenosu e-mailu. V případě, že je tento e-mail součástí obchodního jednání: - vyhrazuje si odesílatel právo ukončit kdykoliv jednání o uzavření smlouvy, a to z jakéhokoliv důvodu i bez uvedení důvodu. - a obsahuje-li nabídku, je adresát oprávněn nabídku bezodkladně přijmout; Odesílatel tohoto e-mailu (nabídky) vylučuje přijetí nabídky ze strany příjemce s dodatkem či odchylkou. - trvá odesílatel na tom, že příslušná smlouva je uzavřena teprve výslovným dosažením shody na všech jejích náležitostech. - odesílatel tohoto emailu informuje, že není oprávněn uzavírat za společnost žádné smlouvy s výjimkou případů, kdy k tomu byl písemně zmocněn nebo písemně pověřen a takové pověření nebo plná moc byly adresátovi tohoto emailu případně osobě, kterou adresát zastupuje, předloženy nebo jejich existence je adresátovi či osobě jím zastoupené známá. This e-mail and any documents attached to it may be confidential and are intended only for its intended recipients. If you received this e-mail by mistake, please immediately inform its sender. Delete the contents of this e-mail with all attachments and its copies from your system. If you are not the intended recipient of this e-mail, you are not authorized to use, disseminate, copy or disclose this e-mail in any manner. The sender of this e-mail shall not be liable for any possible damage caused by modifications of the e-mail or by delay with transfer of the email. In case that this e-mail forms part of business dealings: - the sender reserves the right to end negotiations about entering into a contract in any time, for any reason, and without stating any reasoning. - if the e-mail contains an offer, the recipient is entitled to immediately accept such offer; The sender of this e-mail (offer) excludes any acceptance of the offer on the part of the recipient containing any amendment or variation. - the sender insists on that the respective contract is concluded only upon an express mutual agreement on all its aspects. - the sender of this e-mail informs that he/she is not authorized to enter into any contracts on behalf of the company except for cases in which he/she is expressly authorized to do so in writing, and such authorization or power of attorney is submitted to the recipient or the person represented by the recipient, or the existence of such authorization is known to the recipient of the person
[R] Factor levels in training set
Hi all, I want to use Supervised Self organizing Maps from Kohonen package for my data. I need to divide my df into training set and test set, but a part of my df contains column with factor levels and I don't know how to bring them into my training set. Currently I use the following command for my training set: dt=sort(sample(nrow(df),nrow(df)*.7)) training=m[dt,] till here I get no error but in the next step which I need to bring my training set in a matrix I face this error: scale(df[training,]) error: 'x' should be numeric Does anyone know how should I include column with factor levels in my df so that I don't get this error? Thanks for any help, Elahe __ R-help@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.
[R] Factor levels in training set
Hi all, I want to use Supervised Self organizing Maps from Kohonen package for my data. I need to divide my df into training set and test set, but a part of my df contains column with factor levels and I don't know how to bring them into my training set. Currently I use the following command for my training set: dt=sort(sample(nrow(df),nrow(df)*.7)) training=m[dt,] till here I get no error but in the next step which I need to bring my training set in a matrix I face this error: scale(df[training,]) error: 'x' should be numeric Does anyone know how should I include column with factor levels in my df so that I don't get this error? Thanks for any help, Elahe __ R-help@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.
Re: [R] factor levels numeric values
Hi, Suppose your data frame is called data and the name of the factor column is named tobeConverted. I have tried this and it worked. Hope this helps. as.numeric(as.character(data$tobeConverted)) -- View this message in context: http://r.789695.n4.nabble.com/factor-levels-numeric-values-tp4699515p4703090.html Sent from the R help mailing list archive at Nabble.com. __ R-help@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.
[R] factor levels numeric values
Hi everybody, I have another question (to which I could not find an answer in my r-books. I am sure, it's not a great issue, but I simply lack of a good idea how to solve this: One of my variables gets imported as a factor instead of a numeric variable. Now I have a... Factor w/ 63 levels 0,0.02,0.03,..: 1 NA NA 1 NA NA 1 1 53 10 ... How can I transform these factor levels into actual values? Thank you very much for any help! David [[alternative HTML version deleted]] __ R-help@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.
Re: [R] factor levels numeric values
Hello, David, take a look at the beginning of the Warning section of ?factor. Hth -- Gerrit Hi everybody, I have another question (to which I could not find an answer in my r-books. I am sure, it's not a great issue, but I simply lack of a good idea how to solve this: One of my variables gets imported as a factor instead of a numeric variable. Now I have a... Factor w/ 63 levels 0,0.02,0.03,..: 1 NA NA 1 NA NA 1 1 53 10 ... How can I transform these factor levels into actual values? Thank you very much for any help! David [[alternative HTML version deleted]] __ R-help@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. __ R-help@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.
Re: [R] factor levels numeric values
Also look at the Frequently Asked Questions document that comes with your R installation: 7.10 How do I convert factors to numeric? It may happen that when reading numeric data into R (usually, when reading in a file), they come in as factors. If f is such a factor object, you can use as.numeric(as.character(f)) to get the numbers back. More efficient, but harder to remember, is as.numeric(levels(f))[as.integer(f)] In any case, do not call as.numeric() or their likes directly for the task at hand (as as.numeric() or unclass() give the internal codes). - David L Carlson Department of Anthropology Texas AM University College Station, TX 77840-4352 -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Gerrit Eichner Sent: Wednesday, November 12, 2014 8:06 AM To: David Studer Cc: r-help@r-project.org Subject: Re: [R] factor levels numeric values Hello, David, take a look at the beginning of the Warning section of ?factor. Hth -- Gerrit Hi everybody, I have another question (to which I could not find an answer in my r-books. I am sure, it's not a great issue, but I simply lack of a good idea how to solve this: One of my variables gets imported as a factor instead of a numeric variable. Now I have a... Factor w/ 63 levels 0,0.02,0.03,..: 1 NA NA 1 NA NA 1 1 53 10 ... How can I transform these factor levels into actual values? Thank you very much for any help! David [[alternative HTML version deleted]] __ R-help@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. __ R-help@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. __ R-help@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.
Re: [R] factor levels numeric values
I have not completely followed the discussion, so excuse me if it was already pointed out. If numeric data are read as factors, this means that there are not only numeric data in the column. It could be an empty space somewhere, or some character that should be NA, or... I think it is worth spending some time searching for the typo so that the file will be read correctly in R. HTH, Ivan -- Ivan Calandra, ATER University of Reims Champagne-Ardenne GEGENA² - EA 3795 CREA - 2 esplanade Roland Garros 51100 Reims, France +33(0)3 26 77 36 89 ivan.calan...@univ-reims.fr https://www.researchgate.net/profile/Ivan_Calandra Le 12/11/14 15:56, David L Carlson a écrit : Also look at the Frequently Asked Questions document that comes with your R installation: 7.10 How do I convert factors to numeric? It may happen that when reading numeric data into R (usually, when reading in a file), they come in as factors. If f is such a factor object, you can use as.numeric(as.character(f)) to get the numbers back. More efficient, but harder to remember, is as.numeric(levels(f))[as.integer(f)] In any case, do not call as.numeric() or their likes directly for the task at hand (as as.numeric() or unclass() give the internal codes). - David L Carlson Department of Anthropology Texas AM University College Station, TX 77840-4352 -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Gerrit Eichner Sent: Wednesday, November 12, 2014 8:06 AM To: David Studer Cc: r-help@r-project.org Subject: Re: [R] factor levels numeric values Hello, David, take a look at the beginning of the Warning section of ?factor. Hth -- Gerrit Hi everybody, I have another question (to which I could not find an answer in my r-books. I am sure, it's not a great issue, but I simply lack of a good idea how to solve this: One of my variables gets imported as a factor instead of a numeric variable. Now I have a... Factor w/ 63 levels 0,0.02,0.03,..: 1 NA NA 1 NA NA 1 1 53 10 ... How can I transform these factor levels into actual values? Thank you very much for any help! David [[alternative HTML version deleted]] __ R-help@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. __ R-help@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. __ R-help@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. __ R-help@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.
Re: [R] factor levels numeric values
Another approach is to re-import your data using options that do not put the data into a factor in the first place. For example you can use the colClasses parameter in the read.table family of functions to specify numeric for that column. If you need to give special handling to that column anyway (using strong functions) then you can use the stringsAsFactors=FALSE or as.is=TRUE parameter settings and avoid the as.character() band-aid in your code. --- Jeff NewmillerThe . . Go Live... DCN:jdnew...@dcn.davis.ca.usBasics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/BatteriesO.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --- Sent from my phone. Please excuse my brevity. On November 12, 2014 6:56:11 AM PST, David L Carlson dcarl...@tamu.edu wrote: Also look at the Frequently Asked Questions document that comes with your R installation: 7.10 How do I convert factors to numeric? It may happen that when reading numeric data into R (usually, when reading in a file), they come in as factors. If f is such a factor object, you can use as.numeric(as.character(f)) to get the numbers back. More efficient, but harder to remember, is as.numeric(levels(f))[as.integer(f)] In any case, do not call as.numeric() or their likes directly for the task at hand (as as.numeric() or unclass() give the internal codes). - David L Carlson Department of Anthropology Texas AM University College Station, TX 77840-4352 -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Gerrit Eichner Sent: Wednesday, November 12, 2014 8:06 AM To: David Studer Cc: r-help@r-project.org Subject: Re: [R] factor levels numeric values Hello, David, take a look at the beginning of the Warning section of ?factor. Hth -- Gerrit Hi everybody, I have another question (to which I could not find an answer in my r-books. I am sure, it's not a great issue, but I simply lack of a good idea how to solve this: One of my variables gets imported as a factor instead of a numeric variable. Now I have a... Factor w/ 63 levels 0,0.02,0.03,..: 1 NA NA 1 NA NA 1 1 53 10 ... How can I transform these factor levels into actual values? Thank you very much for any help! David [[alternative HTML version deleted]] __ R-help@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. __ R-help@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. __ R-help@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. __ R-help@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.
Re: [R] Factor levels.
On 3/10/2007, at 5:48 PM, Peter Dalgaard wrote:
Rolf Turner wrote:
I have factors with levels ``Unit, Achieved, and Scholarship;
I wish to replace these with
U, A, and S.
So I do
fff - factor(fff,labels=c(U,A,S))
This works as long as all of the levels are actually present in
the factor. But if ``Scholarship'' is absent
(as if often is) then I get an error.
I can do a workaround such as
fff - factor(c(U,A,S)[fff],levels=c(U,A,S))
but this seems kludgy to me.
Does it even work? (What if it is the first or the 2nd level that
is absent?
Yes it works. What's the problem?
To beat it to death: if the second level of fff is absent then fff
will consist entirely of 1's and 3's,
and so c(U,A,S)[fff] will consist entirely of U's and S's. I
can then set the levels to be
c(U,A,S) and get what I want.
Note that if I just did
fff - factor(c(U,A,S)[fff])
in these circumstances, then I would get a factor whose levels were c
(U,S) which is NOT what I want.
(I.e. I want the levels always to be c(U,A,S) irrespective of
what levels are actually present in the factor.)
The canonical way is
factor(fff, levels=c(Unit, Achieved, Scholarship), labels=c
(U,A,S))
Right. That is indeed sexier. Thanks.
cheers,
Rolf
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Re: [R] Factor levels.
On 4/10/2007, at 7:50 AM, Peter Dalgaard wrote:
Rolf Turner wrote:
Does it even work? (What if it is the first or the 2nd level that
is absent?
Yes it works. What's the problem?
To beat it to death: if the second level of fff is absent
then fff will consist entirely of 1's and 3's,
and so c(U,A,S)[fff] will consist entirely of U's and
S's. I can then set the levels to be
c(U,A,S) and get what I want.
You didn't say that fff was numeric.
All factors are numeric.
If fff is a factor, then we have the problem:
attach(read.table(stdin(),header=T))
0: fff
1: Unit
2: Scholarship
3: Scholarship
4: Unit
5:
c(U,A,S)[fff]
[1] A U U A
My original fff is a factor with levels c
(Unit,Achievement,Scholarship). If you make that
adjustment, you get the ``right answer''.
Actually we have another problem too, namely sort order
No, there is no sort order problem. See above.
[Given that the original fff has its levels in the order specified
then Unit maps to U,
Achievement to A, and Scholarship to S.]
cheers,
Rolf
P.S. ***Are*** there any risks/dangers in following Christos
Hatzis' suggestion of simply doing
levels(fff) - c(U,A,S) ???
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Re: [R] Factor levels.
Rolf Turner wrote: P.S. ***Are*** there any risks/dangers in following Christos Hatzis' suggestion of simply doing levels(fff) - c(U,A,S) ??? Not if the levels are right to begin with. Problems only arise if fff somehow becomes a two-level factor, e.g. if you do fff - fff[2:3, drop=TRUE]. Then you can get this effect: fff [1] UnitScholarship Scholarship Unit Levels: Scholarship Unit fff[2:3, drop=TRUE] [1] Scholarship Scholarship Levels: Scholarship fff[-(2:3), drop=TRUE] [1] Unit Unit Levels: Unit ggg - fff[2:3, drop=TRUE] levels(ggg) - c(a,b) ggg [1] a a Levels: a b ggg - fff[-(2:3), drop=TRUE] levels(ggg) - c(a,b) ggg [1] a a Levels: a b -- O__ Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 __ R-help@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.
[R] Factor levels.
I have factors with levels ``Unit, Achieved, and Scholarship; I
wish to replace these with
U, A, and S.
So I do
fff - factor(fff,labels=c(U,A,S))
This works as long as all of the levels are actually present in the
factor. But if ``Scholarship'' is absent
(as if often is) then I get an error.
I can do a workaround such as
fff - factor(c(U,A,S)[fff],levels=c(U,A,S))
but this seems kludgy to me.
Is there a sexier way?
cheers,
Rolf Turner
##
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and provide commented, minimal, self-contained, reproducible code.
Re: [R] Factor levels
If you don't know ahead of time how many columns you have and only that they are a mix of numeric and character (to be converted to factor) then you can do this: DF - read.table(textConnection(Input), header = TRUE, as.is = TRUE) f - function(x) if (is.character(x)) factor(x, levels = unique(x)) else x DF[] - lapply(DF, f) DF On 9/19/07, Sébastien [EMAIL PROTECTED] wrote: Hi Gabor, I am coming back to you about the method you described to me a month ago to define the level order during a read.table call. I initially thought that I would need to apply the 'unique' function on a single column of my dataset, so I only used it after the read.table step (to make my life easier)... Well, I was wrong: I need to reorder all my columns (just to remind you, I don't know the numbers of columns my code has to handle). So, here come troubles. I first tried to apply your code as is, although I thought there might be some problems. The class can actually not be recycled, when a list notation is used (the help says that colClasses character. A vector of classes to be assumed for the columns. Recycled as necessary...). See the following example: ## library(methods) setClass(my.factor) setAs(character, my.factor, function(from) factor(from, levels = unique(from))) Input-a b c d 1 1 175 n f 2 2 102 n j 3 3 187 o n 4 4 106 u g 5 5 102 o v 6 6 133 l x 7 7 149 w q 8 8 122 x p 9 9 151 u r 10 10 134 e g 11 11 170 j q 12 12 103 v n 13 13 153 n w 14 14 106 x x 15 15 185 v x 16 16 102 s p 17 17 181 i h 18 18 192 o k 19 19 161 d f 20 20 158 n q DF - read.table(textConnection(Input), header = TRUE, colClasses = list(c=(my.factor))) levels(DF$c) # properly ordered levels(DF$d) # not reordered ## I also tried that: ## DF - read.table(textConnection(Input), header = TRUE, colClasses = c(my.factor)) levels(DF$c) levels(DF$d) ## In this case, the class is definitely recycled as all the columns of DF are transformed into factors... Not really useful :) I tried to modify the content of the list or my second notation, by including integer or a second my.factor... but I did not have much success. Any idea how to use the class my.factor multiple times ? Thanks in advance Gabor Grothendieck a écrit : Its the same principle. Just change the function to be suitable. This one arranges the levels according to the input: library(methods) setClass(my.factor) setAs(character, my.factor, function(from) factor(from, levels = unique(from))) Input - a b c 1 1 176 w 2 2 141 k 3 3 172 r 4 4 182 s 5 5 123 k 6 6 153 p 7 7 176 l 8 8 170 u 9 9 140 z 10 10 194 s 11 11 164 j 12 12 100 j 13 13 127 x 14 14 137 r 15 15 198 d 16 16 173 j 17 17 113 x 18 18 144 w 19 19 198 q 20 20 122 f DF - read.table(textConnection(Input), header = TRUE, colClasses = list(c = my.factor)) str(DF) On 8/28/07, Sébastien [EMAIL PROTECTED] wrote: Ok, I cannot send to you one of my dataset since they are confidential. But I can produce a dummy mini dataset to illustrate my question. Let's say I have a csv file with 3 columns and 20 rows which content is reproduced by the following line. mydata-data.frame(a=1:20, b=sample(100:200,20,replace=T),c=sample(letters[1:26], 20, replace = T)) mydata a b c 1 1 176 w 2 2 141 k 3 3 172 r 4 4 182 s 5 5 123 k 6 6 153 p 7 7 176 l 8 8 170 u 9 9 140 z 10 10 194 s 11 11 164 j 12 12 100 j 13 13 127 x 14 14 137 r 15 15 198 d 16 16 173 j 17 17 113 x 18 18 144 w 19 19 198 q 20 20 122 f If I had to read the csv file, I would use something like: mydata-data.frame(read.table(file=c:/test.csv,header=T)) Now, if you look at mydata$c, the levels are alphabetically ordered. mydata$c [1] w k r s k p l u z s j j x r d j x w q f Levels: d f j k l p q r s u w x z What I am trying to do is to reorder the levels as to have them in the order they appear in the table, ie Levels: w k r s p l u z j x d q f Again, keep in mind that my script should be used on datasets which content are unknown to me. In my example, I have used letters for mydata$c, but my code may have to handle factors of numeric or character values (I need to transform specific columns of my dataset into factors for plotting purposes). My goal is to let the code scan the content of each factor of my data.frame during or after the read.table step and reorder their levels automatically without having to ask the user to hard-code the level order. In a way, my problem is more related to the way the factor levels are ordered than to the read.table function, although I guess there is a link... Gabor Grothendieck a écrit : Its not clear from your description what you want. Could you be a bit more specific including an example. On 8/28/07, Sébastien [EMAIL PROTECTED] wrote: Thanks Gabor, I have two questions: 1- Is there any difference
