[ncl-talk] doubt if data is being plottted

[Mary Haley]

Geeta,

I tried to run your script, but the data file appears to be bad.

The issue is likely that your non-missing data may not be surrounded by
enough non-missing points. If you have a single valid point or even two
points surrounded on all sides by missing points, then no contour can be
drawn at those points. If you have three dots, then you end up with a
triangular contour that connects the three dots.

If I could open your data file, then I was going to add a call to
gsn_coordinates so I could draw a dot at all your missing and non-missing
locations.

I think you just need to add this to the end of your script:

    mkres = True
    mkres at gsMarkerSizeF            = 2   ; try values from 2 to 30 to
increase/decrease marker size
    mkres at gsMarkerIndex            = 16   ; filled dot

    mkres at gsnCoordsNonMissingColor = "black"
    mkres at gsnCoordsMissingColor    = "red"
    gsn_coordinates(wks,plot,maxZ,mkres)

This should draw the missing data as red dots and the valid data as black
dots.  You will then be able to see if you have valid data that is not
surrounded by enough other valid data.

If your grid is really high-res, then you will just end up with a blob. You
then may need to zoom in on your map area of interest a little to better
see the area with the problem. You already have these settings:

   res at mpMinLatF   =  13.00
   res at mpMaxLatF   =  17.0
   res at mpMinLonF   =  71.0
   res at mpMaxLonF   =  77.0

so to further zoom in on your map, you can change these to the desired
lat/lon area.

--Mary


On Fri, Dec 16, 2016 at 7:36 AM, Geeta Geeta <geetag54 at yahoo.com> wrote:

> Thanks Mary for your valuable support. I really acknowledge that.
> The plot looks different and I could see the Deep Blue Dot too. Pls check
> from line no 5784 and around this (52.05)
>
> My question is that around this point there were non-zero values, so why
> gsn_countour_map is missing some of the data points. and what method of
> filling the contours is used by "cnFillOn = True"  . I have attached my
> output with this.
> I am also sending the data at your ftp address.
>
> My data looks complete now because I can see each and every pixel.
>
>  warm regards
> Geeta.
>
>
> On Thursday, 15 December 2016 10:56 PM, Mary Haley <haley at ucar.edu> wrote:
>
>
> Geeta,
>
> We cannot debug this by simply looking at data values and plots. I do see
> the issue that you are pointing out, but without seeing your code, I can't
> be sure of the problem.
>
> If your value that is 52.05 is surrounded by missing values, then I think
> it's possible it won't show up on the plot. You could try doing a raster
> plot:
>
> res at cnFillMode = "RasterFill"
>
> to see if this changes anything.
>
> If it doesn't, then if you could provide the data and a clean script, this
> would really help.
>
> thanks,
>
> --Mary
>
>
> On Thu, Dec 15, 2016 at 1:48 AM, Geeta Geeta <geetag54 at yahoo.com> wrote:
>
> dear ncl-talk
> I am using a variable called Z_fnl which is filtered for one condition and
> the it is called maxZ. Then maxZ is filtered for 2 conditions and is called
> maxZ_Conv.
>
> Below output is the LIne number ofthe file, Raintype, Lat, Lon, maxZ,
> maxZ_Conv (Output is attatched)
>
>    5843 (118,0) -9999 14.7402 75.7023   0    -9999
>    5844 (118,1) 152 14.7826 75.6777   23.09    -9999
>    5845 (118,2) 210 14.8249 75.6531   34.03    34.03
>    5846 (118,3) 200 14.8669 75.6286   52.05    52.05
>    5847 (118,4) 200 14.9083 75.6044   40.67    40.67
>    5848 (118,5) 210 14.9496 75.5802   22.34    22.34
>    5849 (118,6) 120 14.9906 75.5562   23.75    -9999
>    5850 (118,7) 210 15.0313 75.5322   24.61    24.61
>    5851 (118,8) 210 15.0716 75.5085   36.33    36.33
>    5852 (118,9) 210 15.112 75.4847   42.3    42.3
> Now I am plotting the Raintype and maxZ_Conv for a small area and for a
> large area.
>
> Now my problem is that it looks like that the plots and unable to
> correspond directly to the data. For example, in the line number at 5846
> which has highest value of 52.05 at the point 14.8669/75.6286 . Pls also
> check the lines from 5843-5852.
>
>  (118,3) 200 14.8669 75.6286   52.05    52.05 seems to be missing in the
> plot. At this point the DEEP Blue color is missing.
>
> I m sorry for asking this basic question.
>
>
>
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