Re: Lambert Conformal Corners and Orientation

Thanks, I have defined in igry for medium gray, but how do I specify that
color fill for Canada and Mexico?
 
I appreciate your patience by the way.
 
-William
 
 
In a message dated 4/22/2008 10:35:12 A.M. Central Daylight Time,
haley_at_ucar.edu writes:

On Tue, 22 Apr 2008 Valkhorn_at_aol.com wrote:

> It's really coming together now. The only issue left is that for some
reason
> Canada and Mexico are really violet - any way I could change that to
gray?
>
> NCL Script is attached.
>
> -William

Hi William,

I believe the current color map you're using doesn't
have gray in it. You can verify this by adding
the following call right after gsn_define_colormap:

gsn_draw_colormap(wks)

If you try to use gray, and you don't have gray in your color map,
then NCL will use some 6-cube algorithm to determine the color closest
to gray that's already in your colormap, and this can produce
unexpected results.

You need to add gray, using the same NhlNewColor function that was in
the script I sent you yesterday. For any shade of gray, you need to
use RGB values that are equal. For example:

igry = NhlNewColor(wks,0.5,0.5,0.5)
igry = NhlNewColor(wks,0.25,0.25,0.25)
igry = NhlNewColor(wks,0.80,0.80,0.80)

The larger the number, the lighter the gray.

You can then use the integer returned from this function, "igry"
to set the color for Canada and Mexico.

--Mary

>
> In a message dated 4/21/2008 4:13:11 P.M. Central Daylight Time,
> haley_at_ucar.edu writes:
>
>
> Hi Valkhorn,
>
> I think the problem is that you have res_at_tfDoNDCOverlay set to True,
> which tells NCL that you don't want the data to go through any kind of
> transformation when it is drawn on the plot. NCL hence tries to draw
> the data (contours) in the same space as what you set up the map to
> be, which, in this case, is a larger area than the actual space that
> the data resides in.
>
> Try commenting out this resource, and see if the results look more
> like what you were expecting.
>
> I added a light blue color to the end of your color map, and then used
> this to fill your ocean in this color. If you don't like the color I
> chose, then you can either pick a different color in
> your existing color map, and use this index value as the
> value to "res_at_mpOceanFillColor".
>
> Or, if you want a different color, you can go to:
>
> http://www.ncl.ucar.edu/Document/Graphics/named_colors.shtml
>
> to look at some colors. Click on any one of the thumbnails to see a
> larger image. Once you find the name of a color you like, say, "pale
> turquoise" (which is what I used here), then go to:
>
> http://www.ncl.ucar.edu/Applications/Scripts/rgb.txt
>
> and find that color in the list. This will give you the RGB
> triplet:
>
> 175 238 238 pale turquoise
>
> Divide these three numbers by 255, and these are the three numbers you
> can use in the call to "NhlNewColor". I've attached the script so you
> can see what I'm talking about.
>
> I can see where this is kind of tedious. I will look into having
> a new function that allows you to add a new color by name, rather
> than by RGB triplet. For example:
>
> ltblue = NhlNewNamedColor(wks,"PaleTurquoise")
>
> --Mary
>
>
> On Fri, 18 Apr 2008 Valkhorn_at_aol.com wrote:
>
>> So I'm finally figuring out how to use this software, and I must say it's
>> pretty amazing. I have a few questions though with the script below:
>>
>> ;*******************************************************
>> ; lcnative_2.ncl
>> ;*******************************************************
>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
>> begin
>> ;************************************************
>> ; open file and read in data
>> ;************************************************
>> stationfile="data.txt"
>> ;
>> ; -1 means read all rows into a one-dimensional variable,
>> ; ATTENTION, DO NOT READ STRINGS.
>> ;
>> dummy = asciiread(stationfile,-1,"float")
>> ncol = 3 ; number of columns is 3
>> npts = dimsizes(dummy)/ncol ; get number of points
>>
>> stationdata = onedtond(dummy,(/npts,ncol/)) ; npts x ncol
>>
>> vpt = stationdata(:,2) ; station data
>> lat = stationdata(:,0) ; latitude values
>> lon = stationdata(:,1) ; longitude values
>> ;************************************************
>> ; create plot
>> ;************************************************
>> wks_type = "pdf"
>> wks_type_at_wkOrientation = "portrait"
>> wks = gsn_open_wks(wks_type,"map") ; open a workstation
>> gsn_define_colormap(wks,"WhViBlGrYeOrReWh") ; choose colormap
>>
>> res = True ; plot mods desired
>> res_at_tiMainString = "High Temperature Sample"
>> ;************************************************
>>
>> res_at_mpLimitMode = "Corners" ; choose range of map
>> res_at_mpLeftCornerLatF = 20
>> res_at_mpLeftCornerLonF = -125
>> res_at_mpRightCornerLatF = 55
>> res_at_mpRightCornerLonF = -60
>>
>> ;************************************************
>>
>> res_at_mpProjection = "LambertConformal"
>> res_at_mpLambertParallel1F = 10
>> res_at_mpLambertParallel2F = 10
>> res_at_mpLambertMeridianF = -100
>>
>> res_at_sfXArray = lon
>> res_at_sfYArray = lat
>>
>> res_at_pmTickMarkDisplayMode = "Always"
>> res_at_mpFillOn = True ; turn off map fill
>> res_at_mpOutlineDrawOrder = "PostDraw" ; draw continental outline
> last
>> res_at_mpOutlineBoundarySets = "GeophysicalAndUSStates" ; state boundaries
>> res_at_mpAreaMaskingOn = True
>>
>> ;res_at_mpFillColors = (/0,9,28,25/)
>> ;res_at_mpMaskAreaSpecifiers = (/"Conterminous US"/)
>>
>>
>
;****************************************************************************
>> ; usually, when data is placed onto a map, it is TRANSFORMED to the
> specified
>> ; projection. Since this model is already on a native lambert conformal
> grid,
>> ; we want to turn OFF the tranformation.
>>
>
;****************************************************************************
>> res_at_tfDoNDCOverlay = True
>>
>
;****************************************************************************
>> res_at_cnFillOn = True ; color plot desired
>> res_at_cnLinesOn = False ; turn off contour lines
>> res_at_gsnSpreadColors = True ; use full range of colormap
>> res_at_gsnAddCyclic = False ; regional data
>> res_at_cnFillDrawOrder = "Draw"
>>
>> res_at_pmLabelBarWidthF = 0.9
>>
>> res_at_cnLevelSelectionMode = "ExplicitLevels"
>> res_at_cnLevels = (/-40,-30,-20,-10,0,10,20,30,40,50,60,70,80,90,100,110/)
>>
>> plot = gsn_csm_contour_map(wks,vpt,res)
>>
>> end
>>
>> (And do let me know if the script doesn't show up correctly)
>>
>> The script takes an ascii file that has three columns - Lat, Lon, and a
>> value that I'm plotting
>>
>> Here is the output and data file:
>> _http://68.63.208.24/maplamb.pdf_ (http://68.63.208.24/maplamb.pdf)
>> _http://68.63.208.24/data.txt_ (http://68.63.208.24/data.txt)
>>
>> Here are my questions:
>>
>> 1) The plots are mostly in the eastern US. Yet, it is plotting points all
>> the way to the left of the chart. How can I make it so that it actually
> plots
>> the lat/lon coordinates correctly on the right part of the map? Do I
need
> to
>> code the points differently?
>>
>> 2) It seems to want to guess for points that don't exist - is there any
way
>> I can just leave white space where the points are not there?
>>
>> 3) Can I color the water light blue and set the contour for over land
> only?
>>
>> Thanks for your help!
>>
>> -William
>>
>>
>>
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>
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>
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**************Need a new ride? Check out the largest site for U.S. used car
listings at AOL Autos.
(http://autos.aol.com/used?NCID=aolcmp00300000002851)
Received on Tue Apr 22 2008 - 14:49:53 MDT