gplot: automatic scaling of the field?

[jservonnat]

I've never noticed but there is an automatic scaling of the values in the colorbar to display scientific notation of the values, for instance 2.10^3 for 2000, that automatically shows the power 10 in the right string and leave the significant figures for the vertical colorbar. Two points on that:

• I've had errors when specifying min, max and delta on this portion of code (sorry I have to go back on that to reproduce the error), that didn't occur when not specifying delta... which is not so convenient if you want to control the plot parameters
• I would prefer if this was an option, so that we can have full control on the units and values of the colorbar What do you think?

[senesis]

Just a warning : I intend to propose a commit that modifies gplot.ncl in the surroundings of the relevant code lines (with some fix). So, if you go ahead with turning that to an option, please wait for this commit. Anyway, I remember that Ncl is not always smart at displaying very small values in a uniform way along a single colorbar. If you develop that option, you may see that by yourself...