[ncl-talk] Plotting Lat/Lon Points on a map

Barry Lynn barry.h.lynn at gmail.com
Sun May 28 08:21:30 MDT 2017


Tim:

If you can wait a day or two, I suggest you write to:

Carrie.Langston at noaa.gov

and ask Him/Her what is the format of the gridded data and if they have an
NCL program to read it.

It's looks like very useful data once you "crack the code."

Barry

On Sun, May 28, 2017 at 5:09 PM, Tim Melino <melino33 at gmail.com> wrote:

> Barry,
>
> The source of the data is here:
>
> http://www.nssl.noaa.gov/projects/mrms/operational/tables.php
>
>
>
> Tim
>
>
>
> On Sun, May 28, 2017 at 10:03 AM, Barry Lynn <barry.h.lynn at gmail.com>
> wrote:
>
>> Tim:
>>
>> If you write out the latitude and longitude information is is
>> rectilinear?
>>
>> When trying to sort this out, you should first check if the lat/lon can
>> be plotted by a single coordinate or two.  If two, then there is a chance
>> that your grid is not rectilinear, and you will have to account for the
>> distortion in the grid.
>>
>> If there is distortion, then you need to account for it (e.g., Lambert,
>> curvilinear.
>>
>> I can only offer advice at the moment...
>>
>> What is the data source for the data?
>>
>> Barry
>>
>> On Sun, May 28, 2017 at 4:52 PM, Tim Melino <melino33 at gmail.com> wrote:
>>
>>> Hey Barry,
>>>
>>> The only information about the projection was: *grid_type :
>>>  Latitude/Longitude.  *I attached the file!
>>>
>>> Tim
>>>
>>> On Sun, May 28, 2017 at 9:00 AM, Barry Lynn <barry.h.lynn at gmail.com>
>>> wrote:
>>>
>>>> Tim:
>>>>
>>>> Please remind me what the name of the file is.
>>>>
>>>> Also, was there any information at the top of the printing about the
>>>> projection?
>>>>
>>>> Yes, the markers would (could) look off.
>>>>
>>>> On Sun, May 28, 2017 at 3:32 PM, Tim Melino <melino33 at gmail.com> wrote:
>>>>
>>>>> Hi Barry,
>>>>>
>>>>> Here is the information when printing (a). Would the map projection
>>>>> also cause a marker to be printed in the wrong location?
>>>>>
>>>>> Variable: a
>>>>> Type: file
>>>>> filename:       test
>>>>> path:   ./test.grib2
>>>>>    file global attributes:
>>>>>    dimensions:
>>>>>       lat_0 = 30
>>>>>       lon_0 = 40
>>>>>    variables:
>>>>>       float VAR_209_3_34_P0_L102_GLL0 ( lat_0, lon_0 )
>>>>>          center :       US NOAA Office of Oceanic and Atmospheric
>>>>> Research
>>>>>          production_status :    Research products
>>>>>          long_name :    unknown variable name
>>>>>          units :        unknown
>>>>>          _FillValue :   1e+20
>>>>>          grid_type :    Latitude/longitude
>>>>>          parameter_discipline_and_category :    209, 3
>>>>>          parameter_template_discipline_category_number :        ( 0,
>>>>> 209, 3, 34 )
>>>>>          level_type :   Specific altitude above mean sea level (m)
>>>>>          level :        500
>>>>>          forecast_time :        0
>>>>>          forecast_time_units :  minutes
>>>>>          initial_time : 07/09/2016 (04:46)
>>>>>
>>>>>       float lat_0 ( lat_0 )
>>>>>          long_name :    latitude
>>>>>          grid_type :    Latitude/Longitude
>>>>>          units :        degrees_north
>>>>>          Dj :   0.01
>>>>>          Di :   0.009999676
>>>>>          Lo2 :  280.735
>>>>>          La2 :  36.695
>>>>>          Lo1 :  280.345
>>>>>          La1 :  36.405
>>>>>
>>>>>       float lon_0 ( lon_0 )
>>>>>          long_name :    longitude
>>>>>          grid_type :    Latitude/Longitude
>>>>>          units :        degrees_east
>>>>>          Dj :   0.01
>>>>>          Di :   0.009999676
>>>>>          Lo2 :  280.735
>>>>>          La2 :  36.695
>>>>>          Lo1 :  280.345
>>>>>          La1 :  36.405
>>>>>
>>>>>
>>>>> On Sun, May 28, 2017 at 12:48 AM, Barry Lynn <barry.h.lynn at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> Hi:
>>>>>>
>>>>>> When the data is skewed, it is often because the projection you're
>>>>>> reading is not the one your plotting.
>>>>>>
>>>>>> Do you know the projection of the data you're using?
>>>>>>
>>>>>> If you print(a) where a is the file you specify from addfile, you can
>>>>>> see the variables (and hopefully projection) indicated within.
>>>>>>
>>>>>> Barry
>>>>>>
>>>>>> On Sat, May 27, 2017 at 4:20 PM, Tim Melino <melino33 at gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> I am attempting to plot a subset of the MRMS data from NCEP.  The
>>>>>>> latitude and longitude I am plotting is :
>>>>>>>
>>>>>>> LAT: 36.5459089
>>>>>>> LON: -79.4585847
>>>>>>>
>>>>>>> I attached an image of the output along with the grib file I am
>>>>>>> using for input. I am noticing a couple things  first the data appears to
>>>>>>> be skewed, so I am not sure if it is an issue with the map projection.
>>>>>>> Second the point which should be plotted in Virginia is actually plotted in
>>>>>>> North Carolina, the only thing that I have been able to do if offset the
>>>>>>> marker to compensate for the issue. Does anyone have any ideas on how to
>>>>>>> fix these issues? Any ideas would be greatly appreciated!
>>>>>>>
>>>>>>> Thanks!
>>>>>>> Tim
>>>>>>>
>>>>>>> Code:
>>>>>>>
>>>>>>> load "$NCARG_ROOT/lib/ncarg/nclscripts/wrf/WRFUserARW.ncl"
>>>>>>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
>>>>>>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
>>>>>>>
>>>>>>> begin
>>>>>>>
>>>>>>> lati=LAT
>>>>>>> loni=LON
>>>>>>> date=DATE
>>>>>>> address=ADDRESS
>>>>>>>
>>>>>>>
>>>>>>> ; Convert the Lat/Lon to a Float
>>>>>>> latc= stringtofloat(lati)
>>>>>>> lonc = stringtofloat(loni)
>>>>>>>
>>>>>>> ; Set the Map Bounds
>>>>>>> minlat = latc - .12
>>>>>>> maxlat = latc + .12
>>>>>>> minlon = lonc - .15
>>>>>>> maxlon = lonc + .15
>>>>>>>
>>>>>>>
>>>>>>>   ;========================
>>>>>>>   ; get list of all files and open as "one big file"
>>>>>>>   ;========================
>>>>>>>   a = addfile( "./" + lati + "_" + loni + ".grib2","r")
>>>>>>>
>>>>>>>   type = "png"
>>>>>>>   wks = gsn_open_wks(type,"./" + lati + "" + loni + ".png")
>>>>>>>
>>>>>>> ; Set some Basic Plot options
>>>>>>>   res = True
>>>>>>>   res at gsnDraw      =  False                   ; do not draw the plot
>>>>>>>   res at gsnFrame     =  False                   ; do not advance the
>>>>>>> frame
>>>>>>>   pltres = True
>>>>>>>   pltres at NoTitles = True
>>>>>>>   pltres at CommonTitle = True
>>>>>>>   pltres at PlotTitle = ""
>>>>>>>   pltres at PanelPlot = True
>>>>>>>   pltres at FramePlot = False
>>>>>>>
>>>>>>> ; Set the Colormap
>>>>>>>   gsn_define_colormap(wks,"hail")
>>>>>>>     lat  = a->lat_0
>>>>>>>     lon  = a->lon_0
>>>>>>>     water = a->VAR_209_3_34_P0_L102_GLL0(:,:)
>>>>>>>     hail = water  *0.0393701;
>>>>>>>
>>>>>>>
>>>>>>>   ; Plotting options for Hail
>>>>>>>   res at gsnMaximize = True
>>>>>>>   res at mpGeophysicalLineThicknessF = 4.0
>>>>>>>   ;res at mpProjection      = "LambertConformal"
>>>>>>>   res at mpGridLineThicknessF        = 0.5
>>>>>>>   res at mpLimbLineThicknessF        = 4.0
>>>>>>>   res at mpNationalLineThicknessF    = 4.0
>>>>>>>   res at mpUSStateLineThicknessF     = 4.0
>>>>>>>   res at mpProvincialLineThicknessF  = 4.0
>>>>>>>   res at mpOutlineBoundarySets = "AllBoundaries"
>>>>>>>   res at mpDataBaseVersion     = "Ncarg4_1"
>>>>>>>   res at mpDataSetName         = "Earth..4"
>>>>>>>   res at mpFillOn            = False         ; fill continents
>>>>>>>   res at mpPerimOn           = False        ; no box around map
>>>>>>>   res at tiMainOn = True
>>>>>>>   res at tiMainFontColor = "Black"
>>>>>>>   res at tiMainString =""
>>>>>>>   res at tiXAxisString   = ""
>>>>>>>   res at tiYAxisString   = ""
>>>>>>>   res at gsnLeftString   = "Date: " + date               ; add the gsn
>>>>>>> titles
>>>>>>>   res at gsnRightString  = ""
>>>>>>>   res at gsnStringFontHeightF = 0.016
>>>>>>>   res at cnInfoLabelOrthogonalPosF = 0.07  ; offset second label
>>>>>>> information
>>>>>>>   res at gsnContourLineThicknessesScale = 0.001
>>>>>>>   res at cnFillOn = True
>>>>>>>   res at lbTitleOn = True                                 ; remove
>>>>>>> field name from label bar
>>>>>>>
>>>>>>>  ; Set the Map Bounds
>>>>>>>         res at sfYArray = lat
>>>>>>>         res at sfXArray = lon
>>>>>>>         res at mpLimitMode                 = "LatLon"
>>>>>>>         res at mpMinLatF                   = minlat
>>>>>>>         res at mpMaxLatF                   = maxlat
>>>>>>>         res at mpMinLonF                   = minlon
>>>>>>>         res at mpMaxLonF                   = maxlon
>>>>>>>         res at tmXBOn = False
>>>>>>>         res at tmYLOn = False
>>>>>>>         res at tmXTOn = False
>>>>>>>         res at tmYROn = False
>>>>>>>         res at gsnAddCyclic                = False
>>>>>>>         res at tfDoNDCOverlay              = False            ; do not
>>>>>>> transform data
>>>>>>>         res at cnLevelSelectionMode = "ExplicitLevels"   ; set
>>>>>>> explicit contour levels
>>>>>>>         res at cnLevels    = (/  0.5,0.75, 1.00, 1.25, 1.50, 1.75,
>>>>>>> 2.00, 2.50, 3.00, 3.50, 4.00, 4.50, 5.00/)   ; set levels
>>>>>>>         res at tiMainFontHeightF     = 0.018               ; font
>>>>>>> height of title
>>>>>>>         res at lbAutoManage          = False             ; we control
>>>>>>> label bar
>>>>>>>         res at pmLabelBarDisplayMode = "Always"          ; turns on
>>>>>>> label bar
>>>>>>>         res at lbOrientation         = "Horizontal"      ; ncl default
>>>>>>> is vertical
>>>>>>>         res at pmLabelBarSide        = "Bottom"          ; default is
>>>>>>> right
>>>>>>>         res at lbLabelStride         = 1                 ; skip every
>>>>>>> other label
>>>>>>>         res at pmLabelBarWidthF      = 0.7               ; default is
>>>>>>> shorter
>>>>>>>         res at pmLabelBarHeightF     = 0.1               ; default is
>>>>>>> taller
>>>>>>>         res at lbLabelFontHeightF    = .012              ; default is
>>>>>>> HUGE
>>>>>>>         res at lbPerimOn             = False             ; default has
>>>>>>> box
>>>>>>>         res at lbTitleString = "Hail Size (Inches)"
>>>>>>>         res at lbTitleFontHeightF = 0.012
>>>>>>>         plot = gsn_csm_contour_map(wks,hail,res)
>>>>>>>
>>>>>>> ; Setup the point
>>>>>>>  mstring1 = "z"
>>>>>>>  fontnum1 = 35
>>>>>>>  xoffset1 = .4
>>>>>>>  yoffset1 = .7
>>>>>>>  ratio1   = 0.0
>>>>>>>  size1    = 1.0
>>>>>>>  angle1   = 0.0
>>>>>>>
>>>>>>>  Tm_index = NhlNewMarker(wks, mstring1, fontnum1, xoffset1,
>>>>>>> yoffset1, ratio1, size1, angle1)
>>>>>>>
>>>>>>>             ; Plot the sites and label them
>>>>>>>                 gres = True
>>>>>>>                 gres at gsMarkerIndex = Tm_index ; 16
>>>>>>>                 gres at gsMarkerSizeF = 0.015 ; .009
>>>>>>>                 gres at gsMarkerColor = "black"
>>>>>>>                 gres at txFont ="helvetica-bold"
>>>>>>>                 gres at txFontHeightF = "25"
>>>>>>>
>>>>>>> site = (/address/)
>>>>>>> lats = (/latc/)
>>>>>>> lons = (/lonc/)
>>>>>>>
>>>>>>> dot = gsn_add_polymarker(wks,plot,lons,lats,gres)
>>>>>>> tlats =lats + .03
>>>>>>> tlons =lons
>>>>>>> text = gsn_add_text(wks,plot,site,tlons,tlats ,gres)
>>>>>>>
>>>>>>> ; Draw the graphics
>>>>>>>   draw(plot)
>>>>>>>   frame(wks)
>>>>>>>
>>>>>>>  end
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> ncl-talk mailing list
>>>>>>> ncl-talk at ucar.edu
>>>>>>> List instructions, subscriber options, unsubscribe:
>>>>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Barry H. Lynn, Ph.D
>>>>>> Senior Lecturer,
>>>>>> The Institute of the Earth Science,
>>>>>> The Hebrew University of Jerusalem,
>>>>>> Givat Ram, Jerusalem 91904, Israel
>>>>>> Tel: 972 547 231 170
>>>>>> Fax: (972)-25662581
>>>>>>
>>>>>> C.E.O, Weather It Is, LTD
>>>>>> Weather and Climate Focus
>>>>>> http://weather-it-is.com
>>>>>> Jerusalem, Israel
>>>>>> Local: 02 930 9525
>>>>>> Cell: 054 7 231 170
>>>>>> Int-IS: x972 2 930 9525
>>>>>> US 914 432 3108 <(914)%20432-3108>
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Barry H. Lynn, Ph.D
>>>> Senior Lecturer,
>>>> The Institute of the Earth Science,
>>>> The Hebrew University of Jerusalem,
>>>> Givat Ram, Jerusalem 91904, Israel
>>>> Tel: 972 547 231 170
>>>> Fax: (972)-25662581
>>>>
>>>> C.E.O, Weather It Is, LTD
>>>> Weather and Climate Focus
>>>> http://weather-it-is.com
>>>> Jerusalem, Israel
>>>> Local: 02 930 9525
>>>> Cell: 054 7 231 170
>>>> Int-IS: x972 2 930 9525
>>>> US 914 432 3108 <(914)%20432-3108>
>>>>
>>>
>>>
>>
>>
>> --
>> Barry H. Lynn, Ph.D
>> Senior Lecturer,
>> The Institute of the Earth Science,
>> The Hebrew University of Jerusalem,
>> Givat Ram, Jerusalem 91904, Israel
>> Tel: 972 547 231 170
>> Fax: (972)-25662581
>>
>> C.E.O, Weather It Is, LTD
>> Weather and Climate Focus
>> http://weather-it-is.com
>> Jerusalem, Israel
>> Local: 02 930 9525
>> Cell: 054 7 231 170
>> Int-IS: x972 2 930 9525
>> US 914 432 3108 <(914)%20432-3108>
>>
>
>


-- 
Barry H. Lynn, Ph.D
Senior Lecturer,
The Institute of the Earth Science,
The Hebrew University of Jerusalem,
Givat Ram, Jerusalem 91904, Israel
Tel: 972 547 231 170
Fax: (972)-25662581

C.E.O, Weather It Is, LTD
Weather and Climate Focus
http://weather-it-is.com
Jerusalem, Israel
Local: 02 930 9525
Cell: 054 7 231 170
Int-IS: x972 2 930 9525
US 914 432 3108
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20170528/c5db9739/attachment.html 


More information about the ncl-talk mailing list