Re: Strange pattern fill issue with stippling when plotting wind barbs.

Hi Philippe,

After looking through the wind-barb code, I am all but certain your
speculation is correct! It will take some more time to gen-up an example
and test the fix, but the fix looks to be a one-liner. Unfortunately, I
can't come up with a work-around -- this happens at such a low level in the
graphics code, its hard to undo the change-of-state from the NCL level.

The best I may be able to do is to get you a new ncl binary once a fix is
tested/verified. For that, I would need to know what system you are using:

  uname -a

In the meantime, I'm filing this as a bug, and I will also make or amend a
ticket for an option to thicken up patterned lines.

Thanks for your awesome clues in pinpointing the issue!
Rick



On Sun, Jun 8, 2014 at 9:43 PM, Philippe Papin <ppapin@albany.edu> wrote:

> Hi NCL talk,
>
> I've been making a series of images that use the stipple pattern fill
> option for a contour interval. However, I've encountered some strange
> behavior when this stippling is used for multiple images created using a do
> loop. I am using *NCL* *v.6.1.2* to make these images.
>
> The datasets and resources used to create these two figures are identical,
> the only difference being that a counter was incremented using a do loop to
> make another image.
>
> Here are two images:
>
> *First image: *
> http://www.atmos.albany.edu/student/ppapin/lb13_img/test/pure_gyre_sr_comp_850geo_test_0.png
>
> *Second image (after incrementing looper by one)*
>
> http://www.atmos.albany.edu/student/ppapin/lb13_img/test/pure_gyre_sr_comp_850geo_test_1.png
>
> As you can see, the stippling does not display the same way, with the
> second image having "hollow" stipple dots rather than the filled stipple
> dots of the first image.
>
> Here are the resources used to create the pattern fill stippling:
>
> * cssres@cnLinesOn = True*
> * cssres@cnFillOn = True*
> * cssres@cnLevelSelectionMode = "ExplicitLevels"*
> * cssres@cnLevels = (/95/) ; set the contour levels*
> * cssres@cnFillColors = (/"transparent","gray20"/)*
> * cssres@cnLineLabelPlacementMode = "Constant"*
> * cssres@cnLineThicknessF = 3.0 *
>
> * cssres@cnFillPattern = 17*
> * cssres@cnFillScaleF = .7*
> * cssres@cnFillDotSizeF = .0045*
> * cssres@cnLineColor = "gray20"*
> * cssres@cnLineLabelsOn = False*
> * cssres@cnInfoLabelOn = False *
> * cssres@lbLabelBarOn = False*
>
> And when plotting:
>
> *do i=0,1*
>
>
> *mpid = gsn_csm_map(wks,mpres)*
> *vcid = gsn_csm_vector(wks,u850_anom,v850_anom,vcres)*
> *ssid = gsn_csm_contour(wks,g850_ss,cssres)*
>
> *overlay(mpid,ssid)*
> *overlay(mpid,vcid)*
>
> *....*
>
> *end do*
>
> My hypothesis after a little bit of testing is that the vector plot option *vcres@vcGlyphStyle
> = "WindBarb"* is modifying the way the stippling is displayed,
> transforming the stipple dot objects from solid to hollow (so that the calm
> hollow circle for wind barbs can be plotted). The problem is these dots
> don't change back to solid for the *cssres* resource the next time the
> image is plotted.
>
> Is there away around this? I can just rearrange the way I am overlaying
> the patterned contour so that the two images plot the same way, but I'd
> rather have solid filled stippling dots, and that doesn't seem possible
> when I am also plotting wind barb vector objects.
>
> I'd be happy to provide more code to troubleshoot, although the script
> this is from is a bit cumbersome, so I hope these snippets are enough to
> diagnose my problem.
>
> Thanks,
> -Philippe
>
> P.S. I dug around the ncl-talk archives, and saw a previous thread stating
> there currently is no way to make *thicker* pattern lines from the available
> options
> <https://www.ncl.ucar.edu/Document/Graphics/Images/fillpatterns.png> other
> than just changing the scaling. Count me as one of those that would like to
> see an option to make thicker patterned lines.
>
>
> -------------------------------------
> Philippe P. Papin
> Dept. of Atmospheric and Environmental Sciences
> University at Albany, SUNY
> 1400 Washington Ave, Albany, NY 12222
> http://www.atmos.albany.edu/student/ppapin/
>
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Received on Wed Jun 11 09:32:47 2014