Combining dotplot R - r

Question

Im trying to combine two plots into the same plot in R.
My code looks like this:
#----------------------------------------------------------------------------------------#
# RING data: Mikkel
#----------------------------------------------------------------------------------------#
# Set working directory
setwd("/Users/mikkelastrup/Dropbox/Master/RING R")
#### Read data & Converting factors ####
dat <- read.table("R SUM kopi.txt", header=TRUE)
str(dat)
dat$Vial <- as.factor(dat$Vial)
dat$Line <- as.factor(dat$Line)
dat$rep <- as.factor(dat$rep)
dat$fly <- as.factor(dat$fly)
str(dat)
mtdata <- droplevels(dat[dat$Line=="20",])
mt1data <- droplevels(mtdata[mtdata$rep=="1",])
tdata <- melt(mt1data, id=c("rep","Conc","Sex","Line","Vial", "fly"))
tdata$variable <- as.factor(tdata$variable)
tfdata <- droplevels(tdata[tdata$Sex=="f",])
tmdata <- droplevels(tdata[tdata$Sex=="m",])
####Plotting####
d1 <- dotplot(tfdata$value~tdata$variable|tdata$Conc,
main="Y Position over time Line 20 Female",
xlab="Time", ylab="mm above buttom")
d2 <- dotplot(tmdata$value~tdata$variable|tdata$Conc,
main="Y Position over time Line 20 Male",
xlab="Time", ylab="mm above buttom")
grid.arrange(d1,d2,ncol=2)
And that looks like this:
Im trying to combine it into one plot, with two different colors for male and female, i have tried to write it into one dotplot separated by a , and or () but that dosen't work and when i dont split the data and use tdata instead of tfdata and tfmdata i get all the dots in the same color. Im open to suggestions, using another package or another way of plotting the data that still looks somewhat like this since im new to R

Answer 1

All you need to do is to use the group parameter.
dotplot(value~variable|Conc, group=Sex, data=tdata,
main="Y Position over time Line 20 All",
xlab="Time", ylab="mm above buttom")
Also, don't use the $ notation in these functions; notice that you're using value from tfdata but value and variable from tdata. This is a problem because there's twice as many rows in tdata! Instead, use the data argument to specify which data frame to get the variables from.