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