Problem:

The “contour” routine refuses to accept the “c_value” keyword for specifying the desired values of the contours to plot.

> IDL> contour,x2arr,pxarr,pyarr,/overplot,c_value=cvals,$
> IDL> c_color=c.purple,c_line=2,c_thick=thk
> % Keyword C_VALUE not allowed in call to: CONTOUR
> % Execution halted at: $MAIN$ 1 /Volumes/khufu1/dfox/pharos1/dfox/anita/I
> ceCube/ehe_eprobs.pro

I’m at a bit of a loss since the code itself pass all “extra” keywords on to further graphics routines.

> IDL> doc_library,'contour'
>
> ----- Documentation for /Applications/exelis/idl84/lib/graphics/contour.pro -----
> :Description:
> Create IDL Contour graphic.
>
> :Params:
> Array :
> X :
> Y :
>
> :Keywords:
> _REF_EXTRA
>
> :Returns:
> Object Reference

The documentation (via “?” graphical user interface, not copied here) is pretty clear that setting “c_value” keyword is the right way to go here.

Any assistance appreciated!