I guess the problem starts with setting read.table(...dec = ",", ... ). The data in your file are with decimal point.
Without that, it works just fine: > f <- "http://r.789695.n4.nabble.com/file/n4498828/p_diarios.txt"; > df <- read.table( f, header = TRUE ) > log.Price <- log(df$price) > head( log.Price ) [1] 2.893700 3.262701 3.432373 3.545586 3.317816 3.387098 Rgds, Rainer On 2012-03-23 19:47, Natasha Stavros wrote: > As.numeric(as.character(factor.level.to.convert)) > On Mar 23, 2012 11:40 AM, "sandro"<sonav...@gmail.com> wrote: > >> Hello, I am relatively new to using R. >> >> The text file contains the date and price . I want to read and manipulate >> the data in R. However, when I use read.table, it treats all of the data >> as >> "factors" and I do not know how to treat the data as numbers: >> >> http://r.789695.n4.nabble.com/file/n4498828/p_diarios.txt p_diarios.txt >> >> setwd ("C:\\Users\\Sandro\\Dropbox\\R") >> data.precios<- read.table ("p_diarios.txt ", header =TRUE >> , dec=",", sep="\t") >> Time<- data.precios$time # 01.02.2004 - 12.05.2011 >> Price<- data.precios$price # Historical spot price >> log.Price<- log(data.precios$price) >> Error en Math.factor(c(12L, 126L, 213L, 342L, 160L, 186L, 219L, 37L, 54L, >> : >> log not meaningful for factors >> >> As you can see, I cannot calculate the price logarithms. >> >> Any help is appreciated. >> >> Sandro >> >> -- >> View this message in context: >> http://r.789695.n4.nabble.com/How-to-convert-factors-to-numbers- tp4498828p4498828.html >> Sent from the R help mailing list archive at Nabble.com. >> >> ______________________________________________ >> 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. >> > > [[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.
