breeze.viz : plot two objects in same color

Hello,

on several occasions already I needed to plot two objects (eg. dots and a line) in the same color. I would like to avoid specifying the color explicitly but rather use the builtin palette to be robust against possible future changes.

I've checked the plot/package.scala and the plot/PaintScale.scala implementation to find a way, but I do not see anything like this implemented. Do you have any idea?

My next try would have been to explicitly pass the palette PaintScale.Category10 to plot, but it only accepts colorcode: String. A conversion function, the inverse of PaintScale.convertToColor doesn't exist. Do you know a work-around?

Alternatively, would you be interested in a PR for either one of those:

• a new argument to plot, namely color: java.awt.Color to use it like this: color=PaintScale.Category10(1) to get the same color as the second plot
• an inverse conversion function (might be hard to maintain)
• a new magic string to pass to colorcode, indicating to take the same color as plot number x, e.g. colorcode="plot1" to use the same color as the second plot.

Cheers!