[R] How to draw different series for different groups in xyplot

Hi guys, I got a problem when I was trying to use lattice to do some plot. Below is one working example which can generate one curve for A and one curve for B in each subplot. However, I would like to just show the points for B, not connecting the dots. As for A, I still want a curve (dots are con

[R] How to control in order of groups in xyplot

Hi guys, I used the following R code to generate one plot library(lattice) xyplot(Y~X1|as.factor(X2)*as.factor(X3), groups = as.factor(X4), data=mydata) Both X2 and X3 have three values. X4 has two values. I got 3x3 grids and in each grid there are two curves about y~x1 for the two X4 values. I