Hi All, I want to select a level of a factor variable from a dataset. I have the folowing data: dataset: use factor: month (use$month, levels=February, July)> use[1:5,]month registration use department size 1 February KKG151GP Y Safety 1.6 To select February I tried:> use[use$month=="February"]Error in "[.data.frame"(use, use$month == "February") : undefined columns selected> use[use$month == levels(use$month)[1]]Error in "[.data.frame"(use, use$month == levels(use$month)[1]) : undefined columns selected It seems if a logical variable is created, and the subsetting on a factor variable won't work directly.(It works directly for numeric variables) Can anyone help please. Regards Hennie Gerber Hennie Gerber Statistician UNISA - Research Support + 27 12 429 3188 Waarskuwing! Die sienings uitgespreek is my eie en nie noodwendig my werkgewer sin nie Warning! All views expressed are my own and not necessarily that of my employer. --------------------------------------------------------------------------- This message (and attachments) is subject to restrictions and a disclaimer. Please refer to http://www.unisa.ac.za/disclaimer for full details. --------------------------------------------------------------------------- <<<<gwavasig>>>> <<<< gwavasig >>>> [[alternative HTML version deleted]]
Thanks Prof Ripley, It''s working. I understand the whole consept better now(forgot the comma). regards Hennie Gerber Hennie Gerber Statistician UNISA - Research Support + 27 12 429 3188 Waarskuwing! Die sienings uitgespreek is my eie en nie noodwendig my werkgewer sin nie Warning! All views expressed are my own and not necessarily that of my employer. --------------------------------------------------------------------------- This message (and attachments) is subject to restrictions and a disclaimer. Please refer to http://www.unisa.ac.za/disclaimer for full details. --------------------------------------------------------------------------- <<<<gwavasig>>>> <<<< gwavasig >>>> [[alternative HTML version deleted]]
Hi On 6 Apr 2005 at 11:34, H J Gerber wrote:> Hi All, > > I want to select a level of a factor variable from a dataset. I have > the folowing data: dataset: use factor: month (use$month, > levels=February, July) > use[1:5,] > month registration use department size > 1 February KKG151GP Y Safety 1.6 > To select February I tried: > > use[use$month=="February"] > Error in "[.data.frame"(use, use$month == "February") : > undefined columns selectedDimensions! use[use$month=="February",] shall show all columns where use$month = February Cheers Petr> > use[use$month == levels(use$month)[1]] > Error in "[.data.frame"(use, use$month == levels(use$month)[1]) : > undefined columns selected > It seems if a logical variable is created, and the subsetting on a > factor variable won't work directly.(It works directly for numeric > variables) Can anyone help please. > > Regards > Hennie Gerber > > > Hennie Gerber > Statistician > UNISA - Research Support > + 27 12 429 3188 > Waarskuwing! > Die sienings uitgespreek is my eie en nie noodwendig my werkgewer sin > nie Warning! All views expressed are my own and not necessarily that > of my employer. > > > > > > > ---------------------------------------------------------------------- > ----- This message (and attachments) is subject to restrictions and a > disclaimer. Please refer to http://www.unisa.ac.za/disclaimer for full > details. > ---------------------------------------------------------------------- > ----- <<<<gwavasig>>>> <<<< gwavasig >>>> > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at 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.htmlPetr Pikal petr.pikal at precheza.cz