`colorpanel`

generate a set of colors that varies
smoothly. `redgreen`

, `greenred`

, `bluered`

, and
`redblue`

generate red-black-green, green-black-red,
red-white-blue, and blue-white-red colorbars, respectively.
colors

```
colorpanel(n, low, mid, high)
redgreen(n)
greenred(n)
bluered(n)
redblue(n)
```

n

Desired number of color elements in the panel.

low, mid, high

Colors to use for the Lowest, middle,
and highest values. `mid`

may be ommited.

Vector of HTML-style RGB colors.

The values for `low, mid, high`

can be given as
color names ('red'), plot color index (2=red), and HTML-style RGB,
("\#FF0000"=red).

If `mid`

is supplied, then the returned color panel will consist
of `n - floor(n/2)`

HTML-style RGB elements which vary smoothly
between `low`

and `mid`

, then between `mid`

and
`high`

. Note that if `n`

is even, the color `mid`

will
occur twice at the center of the sequence.

If `mid`

is omitted, the color panel will vary
smoothly beween `low`

and `high`

.

# NOT RUN { showpanel <- function(col) { image(z=matrix(1:100, ncol=1), col=col, xaxt="n", yaxt="n" ) } par(mfrow=c(3,3)) # two colors only: showpanel(colorpanel(8,low="red",high="green")) # three colors showpanel(colorpanel(8,"red","black","green")) # note the duplicatation of black at the center, using an odd # number of elements resolves this: showpanel(colorpanel(9,"red","black","green")) showpanel(greenred(64)) showpanel(redgreen(64)) showpanel(bluered(64)) showpanel(redblue(64)) # }