[R] lattice contourplot: how to change line width?

[Luigi Marongiu]

Hello,
I have generated a contourplot with lattice. How do I set the line
width? I tried with:
```
library(lattice)
contourplot(Z ~ X*Y, data = df, cuts = 3,
panel=function(x,y,...){
panel.contourplot(lty=1, lwd = 3)
})
```
but did not work...
Thank you