[R] colour coding and different point types in a plot

[Grum, Mikkel]

I'm trying to plot four different sorghum types on a plot using a different
colour/symbol combination for each sorghum type (TYPBOTA in the script
below).  What am I doing wrong?:

plot(xx$LATITUDE,xx$SFD1,
   points(xx$SFD1,xx$LATITUDE,
   col=1:4[codes(xx$TYPBOTA)],pch=c(4,3,1,2)[codes(xx$TYPBOTA)])
grid()

I get the following error message
Error in 1:4[codes(xx$TYPBOTA)] : NA/NaN argument
In addition: Warning message: 
Numerical expression has 162 elements: only the first used in:
1:4[codes(xx78$TYPBOTA)] 


Best wishes,
Mikkel


Mikkel Grum, PhD
Genetic Diversity Scientist
International Plant Genetic Resources Institute (IPGRI)
Sub-Saharan Africa Group
***
c/o ICRAF
PO Box 30677 Nairobi, Kenya
Tel: 254 2 524505 / 524500
Fax: 254 2 524501 / 524001
IVDN Tel: 645 4505 / 4500
IVDN Fax: 645 4501 / 4001
m.grum at cgiar.org
ipgri-kenya at cgiar.org
www.ipgri.cgiar.org

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