[R] Levelplot of percentages always using 0 to 100 in the color scheme

[Deepayan Sarkar]

On 2/5/08, Kelvin <kjmenzel at cox.net> wrote:
> I am trying to create levelplot's of cpu usage for systems.
> print(levelplot(util.mean ~ x.hour * x.day, colorkey=T, cut=20,
>     scales=list(x=list(at=seq(0,96,length=25),
>         labels=ifelse(seq(0,24) %% 4 == 0, seq(0,24), ''))),   # add
> tick marks at the hour
>     main="CPU Utilization During November on idnprod",
>
> col.regions=colorRampPalette(c('white','green','yellow','red'))(101), #
> 101 colors
>     xlab="Hours (15 minute intervals)", ylab="Day of the Month")
> )
> util.mean has the utilizations by timestamps
> If the values in util.mean are only 10-50, the plot codes 10 as white
> and low and 50 as red and high.
> What I would desire is the 0 is always the low and white and 100 always
> the high and red.

Specify a suitable 'at' argument; e.g.,

at = seq(0, 100, length = 51)

-Deepayan