Re: Problem contouring data

From: David Brown <dbrown_at_nyahnyahspammersnyahnyah>
Date: Thu, 19 Mar 2009 15:03:30 -0600

Hi Jeff,

I think you have stumbled upon a quirk of the area fill mode that
results in no fill if no contour lines (whether lines are turned on
or not)
cross the area bounded by the data coordinate extents.
A workaround is to use the raster mode instead. I was able to get a
single color displayed for the whole plot by setting

res_at_cnFillMode = "RasterFill"

in your script.

Raster fill will most closely resemble area fill if you also set

res_at_cnRasterSmoothingOn = True

Hope this helps.

We will add a to-do item to come up with a way to fix the problem
with area fill.

On Mar 19, 2009, at 10:08 AM, Jeff Van Dorn wrote:

> Yes, I would expect to see just one color/box filled for the plot,
> I know it's not a very descriptive plot, but that is what I'd like
> to see.
> Jeff
> On Mar 19, 2009, at 8:56 AM, Mary Haley wrote:
>> Forgot to CC Dave.
>> On Thu, 19 Mar 2009, Mary Haley wrote:
>>> Jeff,
>>> A question: your data values go from about 2.453 to 2.976. You are
>>> selecting contour levels of 1,2,3,4,....
>>> So, effectively, your data fits between contour levels 2 and 3. In
>>> this case I would expect to see just one box filled in with the same
>>> color. Is this what you wanted?
>>> I'm not sure what happens internally in NCL if all your data fits
>>> between two contours levels. My guess would be that you would get
>>> your plot area filled with one color (which I'm not seeing here).
>>> I've CC'ed Dave. Dave, would you expect a blank screen or one
>>> color? I've attached a pared down version of his script and data.
>>> --Mary
>>> On Thu, 19 Mar 2009, Jeff Van Dorn wrote:
>>>> Hi Mary,
>>>> Thanks for trying to take a look at it, perhaps if you re-
>>>> download the script (
>>>> debugContourPlot.ncl) things will work now. I had forgotten to
>>>> change the debug script to work with the data in the same
>>>> directory as the script, so, hopefully that will solve your
>>>> issue. The file seems to be OK to me, as I'm able
>>>> to ncdump it (ncdump version 3.6.2) and NCL does seem to work
>>>> with it OK, so I'm hoping that the new script will get things
>>>> working.
>>>> Thanks,
>>>> Jeff
>>>> On Mar 19, 2009, at 8:10 AM, Mary Haley wrote:
>>>>> Hi Jeff,
>>>>> I was going to take a look, but I couldn't open your
>>>>> file. It seems like it might
>>>>> not be a NetCDF file.
>>>>> --Mary
>>>>> On Mar 18, 2009, at 4:02 PM, Jeff Van Dorn wrote:
>>>>>> Hello,
>>>>>> I'm hoping someone can help me out as I'm having problems getting
>>>>>> contours/colors to show up on my map when I specify:
>>>>>> res_at_cnLevelSelectionMode = "ManualLevels".
>>>>>> When I plot the area I'm interested in with
>>>>>> res_at_cnLevelSelectionMode
>>>>>> = "AutomaticLevels" I get the following:
>>>>>> 3_model.tavg.annual.
>>>>>> 2025.automatic.gif
>>>>>> Which does show a range of temperature changes from about 2.48 to
>>>>>> 2.96 degrees F.
>>>>>> However, when I change the resources to:
>>>>>> res_at_cnLevelSelectionMode = "ManualLevels"
>>>>>> res_at_cnMinLevelValF = 1
>>>>>> res_at_cnMaxLevelValF = 13
>>>>>> res_at_cnLevelSpacingF = 1
>>>>>> I get the following:
>>>>>> 3_model.tavg.annual.
>>>>>> 2025.manual.gif
>>>>>> Which shows no colors at all, when I'd expect it so show the
>>>>>> single
>>>>>> yellow color between 2 and 3 for the entire map.
>>>>>> Unfortunately I do
>>>>>> need the min/max settings to be 1/13 respectively, so I can't
>>>>>> rely on
>>>>>> the AutomaticLevels for the contours, as I need one constant
>>>>>> temperature scale to correspond to several maps (other maps not
>>>>>> shown, but the range for all maps I need to produce go from 1
>>>>>> to 13).
>>>>>> I'm at a loss as to what to modify to get the colors/contours
>>>>>> to show
>>>>>> up, and will try anything suggested. I've put my script code at:
>>>>>> 3_model.tavg.annual.
>>>>>> 2025.manual.gif
>>>>>> As well as the data (26MB):
>>>>>> ~jvandorn/
>>>>>> ncl/
>>>>>> I'm hoping there's something basic that I'm doing wrong or an
>>>>>> easy
>>>>>> solution. I'm using NCL 5.1.0.
>>>>>> Thanks for any help.
>>>>>> Jeff
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Received on Thu Mar 19 2009 - 15:03:30 MDT

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