[R] lines and points in xyplot()

[Deepayan Sarkar]

On Wed, Nov 23, 2011 at 10:48 PM, Doran, Harold <HDoran at air.org> wrote:
> Given the following data, I want a scatterplot with the data points and the predictions from the regression.
>
> Sigma <- matrix(c(1,.6,1,.6), 2)
> mu <- c(0,0)
> dat <- mvrnorm(5000, mu, Sigma)
>
> x <- dat[,1] * 50 + 200
> y <- dat[,2] * 50 + 200
>
> fm <- lm(y ~ x)
>
> ### This gives the regression line, but not the data
> xyplot(y ~ x,
>               type = c('g', 'p'),
>               panel = function(x, y){
>               panel.lines(x, predict(fm))
>               }
> )
>
> ### This gives both data but as point
> xyplot(y + predict(fm) ~ x,
>               type = c('g', 'p'),
>               )
>
> I know I can add an abline easily, but my problem is a bit more complex and the code above is just an example.
> What is the best way for the predicted data to form a solid line and let the data points remain as points

See

http://lattice.r-forge.r-project.org/Vignettes/src/lattice-tricks/regression-lines.pdf

(This is a work in progress, so feedback would be appreciated.)

-Deepayan