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Re: Interesting IDLgrContour Bug
Did you report this to tech support yet?
David Fanning wrote:
> Hi Folks,
> I ran into an interesting little IDLgrContour bug today
> that gave me a few hours of fun. Apparently, the
> contour algorithm cannot see positive data that is less
> than 1. As a result, it reports the contour range incorrectly.
> Here is a very short example:
> ; Create test data.
> data = Dist(40)
> ; Normalize the Y values from 20 to 39 to be less than 0.
> data[*,20:39] = data[*,20:39]/Max(data)
> ; Create contour plot.
> x = findgen(40)
> y = findgen(40)
> theContour = Obj_New('IDLgrContour', data, Geomx=x, Geomy=y)
> ; Get the Y range of the data.
> theContour->GetProperty, YRange=theBadRange
> ; Print it. Expect 0 to 39.
> Print, theBadRange
> 0.000000 19.8495
> Whoops! Of course, this will cause the scaling to be
> completely off when you go to put the plot into your
> The work around is to get the contour range from
> the X and Y vectors. I don't think too many people
> will run into this, but it can be distracting. :-)
> I've tested this in IDL 5.3.1 and IDL 5.4 beta on
> Windows NT 4.0.
> David Fanning, Ph.D.
> Fanning Software Consulting
> Phone: 970-221-0438 E-Mail: email@example.com
> Coyote's Guide to IDL Programming: http://www.dfanning.com/
> Toll-Free IDL Book Orders: 1-888-461-0155