Hello, this code below was from a helpful R-help user.

dat <- read.csv("Resid_fix2.csv", sep="," , header=T)
dat11 <- dat[1:413,]
# convert ambiguous columns to factors:
dat11$Pri_No <-  factor(dat11$Pri_No)
dat11$RecovUnit <-  factor(dat11$RecovUnit)
# plot:
require(lattice)
bwplot(bbED~ Pri_No | RecovUnit, data=dat11, as.table=TRUE, layout=c(4,1))

This works, but I am trying to do this:
> bwplot(bbED~ Pri_No | RecovUnit, data=dat11, subset = (Pri_No %in%
c(1,2)), as.table=TRUE, layout=c(2,1))
Error in limits.and.aspect(prepanel.default.bwplot, prepanel = prepanel,  :
  need at least one panel

How can I choose only two groups from 'Pri_No'?

Thank you kindly,
Michael Just

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