Re: Unexpected behavior from lgItemOrder

Hi Travis,

I haven't forgotten about this ticket! I was mulling in my head whether this was an issue with the resource or with the actual function.

I'm still not sure which it is, but I appreciate you bringing it to our attention.

I have submitted a ticket for this, NCL-1598. Please refer to this ticket number if you have further questions about this ticket.

Hopefully we'll get a fix in for 6.1.1, maybe early or mid January.

--Mary

On Nov 29, 2012, at 3:55 PM, Travis O'Brien wrote:

> Dear NCL Developers,
>
> I have encountered some unexpected behavior in the usage of lgItemOrder with gsn_legend_ndc() to control the order of legend items. From the documentation, I expect that when I explicitly set lgItemOrder, all aspects of the legend items (including color, dash pattern, and legend string) will be re-ordered accordingly. However, it seems that the legend string is not reordered along with the rest of the legend elements, which leads to a mismatched legend. I have pasted a simple script below my signature to demonstrate this issue. The png generated by this script on my machine can be accessed here: http://dl.dropbox.com/u/43145817/BugReports/lgItemOrder_bug_test.png
>
> The script draws three legends: the first (leftmost) with no reordering, the second (middle) with reordering, and the third (rightmost) with a workaround to produce the expected behavior. The first legend demonstrates the expected correspondence between line color/style and legend string. The second panel demonstrates that the line color/styles are re-ordered, but the legend strings are not, which leads to an inconsistent legend (notice that the color named in the legend string no longer corresponds to the line color). The third panel shows what I expected that lgItemOrder would do in the second panel; I achieved this by passing a manually re-ordered version of the legend strings.
>
> If this is not actually a bug, then perhaps a note might be added to the lgItemOrder documentation to clarify the behavior of this resource.
>
> This test was run with ncl 6.1.0 on a 64-bit Ubuntu 12.04 system (output from uname -a: 3.2.0-33-generic #52-Ubuntu SMP Thu Oct 18 16:29:15 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux).
>
> Please let me know if I can provide any further clarification.
>
> Thank you,
> -Travis-
>
> --
> Travis A. O'Brien
> Climate Science Postdoctoral Fellow
> Lawrence Berkeley National Lab
> http://esd.lbl.gov/about/staff/travisobrien/
>
>
>
>
> __________________________________________________________
>
>
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
>
> begin
>
> ;Set up a simple test with four items. The line labels correspond
> ; to the color of the line, with the number corresponding to the expected
> ; placement when lgItemOrder is used.
> nitems=4
> colors = (/"red","green","cyan","blue"/)
> labels = (/"red - 3","green - 1","cyan - 4","blue - 2"/)
> dashes = (/0,1,2,3/)
>
> res = True
> res@lgLineColors = colors ;Set legend colors
> res@lgDashIndexes = dashes ;Set legend dash patterns
> res@lgLineThicknessF = 5.0 ;Draw thick lines
> ;Give the legend a moderate size so that we can fit two legends
> res@vpWidthF = 0.3
> res@vpHeightF = 0.3
>
> ;Open the worksheet
> wks = gsn_open_wks("png","lgItemOrder_bug_test")
>
> ;Draw the first legened, with the items ordered as explicitly set above.
> ;In this test, the numbers shouldn't match the ordering
> gsn_legend_ndc(wks,nitems,labels,0.0,1.0,res)
>
>
> ;Now set lgItemOrder so that the labels should go in numerical order
> res@lgItemOrder = (/1,3,0,2/)
> ;Draw the second legend, with the items reodered.
> ;In this test, the numbers should match the ordering and the color labels
> ;should match the line colors (they don't in my test)
> gsn_legend_ndc(wks,nitems,labels,0.35,1.0,res)
>
> ;Draw the third legend, with a workaround: provide the labels in the order
> ;explicitly given by res@lgItemOrder
> gsn_legend_ndc(wks,nitems,labels(res@lgItemOrder),0.7,1.0,res)
>
> frame(wks)
>
> end
>
>
>
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Received on Fri Dec 21 09:56:07 2012