On 9/27/2005 12:13 PM, Chris Buddenhagen wrote: > Dear Duncan Murdoch > > Thanks for responding. I will provide more complete info with future > questions. The data for a small pilot study are below. > > The values for each month are the percentage cover of an invasive plant here > in the Galapagos (TT=treatment) type = immediately herbicide applied or > applied to regrowth later. I called the data glyphosate.txt. > > > The code is > > glyp<-read.delim("C:\\Chris\\active projects\\Aristolochia\\glyphosate.txt", > header=T) > list(names(glyp)) > > This is the output that mystified me: > > [1] "TT" "type" "CUADRANTES" "X15dec02" "X15jan03" > [6] "X15feb03" "X15apr03" "X15jun03" "X15aug03" "X15oct03"
It looks as though you have column headings like "15dec02". That's not a legal R variable name, so it prepends the X to make it into one. That way you can do things like glyp$X15dec02 to extract that column. glyp$15dec02 would give a syntax error. > > While I have an expert on hand I have another question, how do I produce a > graph of time against percentage cover with error bars. I wanted to only > present months on the x axis. I start by reorganizing the data using this: Various functions implement error bars, but I haven't used them in a long time, so I'll leave this question for someone else to answer. Duncan Murdoch > > glyp2<-reshape(glyp, direction="long", idvar=c("TT", "type", > "CUADRANTES"),varying=list(names(glyp)[4:10]),v.names="cover") but couldn't > get month names to appear in the column time. > > > > TT type CUADRANTES "15dec02" "15jan03" "15feb03" > "15apr03" "15jun03" "15aug03" "15oct03" > T1 immediate 1 63 59 60 55 4.5 1 > 2 > T1 immediate 2 75 75 75 75 6.5 1 > 2 > T1 immediate 22 72 70 70 65 35 2 > 3.5 > T1 immediate 26 90 80 80 75 17.5 2 > 4 > T1 immediate 33 75 80 85 85 40 1 > 2 > T2 immediate 18 85 80 80 22.5 2.5 2 > 5 > T2 immediate 21 90 85 85 60 16.5 0 > 1 > T2 immediate 23 85 80 80 75 17.5 1 > 2 > T2 immediate 28 90 85 85 27.5 27.5 0 > 1 > T2 immediate 31 90 85 85 9 12.5 1 > 2 > T3 immediate 3 50 58 60 65 35 1 > 2 > T3 immediate 10 63 60 60 15 2.5 0 > 10 > T3 immediate 12 90 85 85 17.5 15 0 > 5 > T3 immediate 16 85 82 80 78 9 1 > 1.5 > T3 immediate 34 75 80 85 85 35 1.5 > 2.5 > T4 wait 4 75 75 75 7.5 2.5 0 0 > T4 wait 11 63 60 60 12.5 2.5 1 2 > T4 wait 24 90 85 80 3.5 5.5 1 2 > T4 wait 29 85 80 80 1.5 4.5 1 2 > T4 wait 32 85 80 80 3.5 4.5 2 3.5 > T5 wait 6 50 50 50 1 1 0.5 2 > T5 wait 14 80 75 75 15 5.5 1 2 > T5 wait 15 90 80 80 1 5.5 1 3 > T5 wait 20 85 80 80 22.5 8.5 0 0 > T5 wait 25 85 80 80 22.5 8.5 1 1.5 > T6 wait 8 75 75 75 1.5 4.5 0 1.5 > T6 wait 9 90 85 85 1.5 3.5 1 2 > T6 wait 13 80 75 75 1 3.5 1 1.5 > T6 wait 19 90 85 80 1 2.5 1 2 > T6 wait 27 85 80 75 1 3.5 1 2 > Tc control 5 50 45 45 40 23 20 25 > Tc control 7 50 53 54 55 55 50 55 > Tc control 17 90 80 70 22.5 9 15 20 > Tc control 30 75 75 70 75 45 60 70 > Tc control 35 90 85 80 85 65 60 70 > > Chris Buddenhagen, Botany Department, Charles Darwin Research Station, Santa > Cruz,Galapagos. Mail: Charles Darwin Foundation, Casilla 17-01-3891 Avenida > 6 de Diciembre N36-109 y Pasaje California Quito, ECUADOR > > > > > > > ______________________________________________________________________ > EL CONTENIDO DE ESTE MENSAJE ES DE ABSOLUTA RESPONSABILIDAD DEL AUTOR. > FUNDACION CHARLES DARWIN > WWW.DARWINFOUNDATION.ORG ______________________________________________ R-help@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.html