[R] Constrain density to 0 at 0?

[David Winsemius]

On Jul 19, 2010, at 9:57 PM, Farley, Robert wrote:

> I'm plotting some trip length frequencies using the following code:
>
> plot( density(zTestData$Distance, weights=zTestData$Actual),
>    xlim=c(0,10),
>    main="Test TLFD",
>    xlab="Distance",
>   col=6  )
> lines(density(zTestData$Distance, weights=zTestData$FlatWeight),  
> col=2)
> lines(density(zTestData$Distance, weights=zTestData$BrdWeight ),  
> col=3)
>
> which works fine except the distances are all positive, but the  
> densities don't drop to 0 until around -2 or -3.
>
> Is there a way for me to "force" the density plot to 0 at 0?

Yes. (Assuming it can be zero, given the data.)

Read the help page for density more carefully. Especially the bw and  
from arguments.

-- 
David.