[ncl-talk] Plotting Lat/Lon Points on a map
Tim Melino
melino33 at gmail.com
Sun May 28 08:09:29 MDT 2017
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>
>
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