mirror of https://github.com/ecmwf/eccodes.git
90 lines
3.1 KiB
Modula-2
90 lines
3.1 KiB
Modula-2
# GRID DEFINITION Polar stereographic
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# grib 1 -> 2
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constant gridDefinitionTemplateNumber = 20;
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unsigned[2] Nx : dump;
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alias Ni = Nx;
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alias numberOfPointsAlongXAxis = Nx;
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alias geography.Nx=Nx;
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unsigned[2] Ny : dump;
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alias Nj = Ny;
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alias numberOfPointsAlongYAxis = Ny;
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alias geography.Ny=Ny;
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signed[3] latitudeOfFirstGridPoint : edition_specific ;
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meta geography.latitudeOfFirstGridPointInDegrees scale(latitudeOfFirstGridPoint,oneConstant,grib1divider,truncateDegrees) : dump;
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alias La1 = latitudeOfFirstGridPoint;
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signed[3] longitudeOfFirstGridPoint : edition_specific;
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meta geography.longitudeOfFirstGridPointInDegrees scale(longitudeOfFirstGridPoint,oneConstant,grib1divider,truncateDegrees) : dump;
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alias Lo1 = longitudeOfFirstGridPoint;
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include "grib1/resolution_flags.def";
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# LoV - orientation of the grid; i.e. the longitude value of the meridian which is parallel to the Y-axis
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signed[3] orientationOfTheGrid ;
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meta geography.orientationOfTheGridInDegrees scale(orientationOfTheGrid,oneConstant,grib1divider,truncateDegrees) : dump;
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alias LoV = orientationOfTheGrid ;
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# Dx - X-direction grid length
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unsigned[3] DxInMetres : dump;
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alias xDirectionGridLengthInMetres=DxInMetres;
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alias Dx=DxInMetres;
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alias geography.DxInMetres=DxInMetres;
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alias Di = DxInMetres;
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# Dy - Y-direction grid length
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unsigned[3] DyInMetres : dump;
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alias yDirectionGridLengthInMetres=DyInMetres;
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alias Dy = DyInMetres;
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alias Dj = DyInMetres;
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alias geography.DyInMetres=DyInMetres;
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constant latitudeWhereDxAndDyAreSpecifiedInDegrees=60;
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constant LaDInDegrees=60;
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alias geography.LaDInDegrees=LaDInDegrees;
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# Projection centre flag
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unsigned[1] projectionCentreFlag : dump ;
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alias projectionCenterFlag=projectionCentreFlag;
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# Note our flagbit numbers go from 7 to 0, while WMO convention is from 1 to 8
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# If bit 1 is 0, then the North Pole is on the projection plane
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# If bit 1 is 1, then the South Pole is on the projection plane
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flagbit southPoleOnProjectionPlane(projectionCentreFlag,7) : dump; # WMO bit 1
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# for change_scanning_direction
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alias yFirst=latitudeOfFirstGridPointInDegrees;
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alias xFirst=longitudeOfFirstGridPointInDegrees;
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include "grib1/scanning_mode.def";
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pad padding_grid5_1(4);
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meta numberOfDataPoints number_of_points(Nx,Ny,PLPresent,pl) : dump;
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alias numberOfPoints=numberOfDataPoints;
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meta numberOfValues number_of_values(values,bitsPerValue,numberOfDataPoints,bitmapPresent,bitmap,numberOfCodedValues) : dump;
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#alias ls.valuesCount=numberOfValues;
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iterator polar_stereographic(numberOfPoints,missingValue,values,
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radius,Nx,Ny,
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latitudeOfFirstGridPointInDegrees,longitudeOfFirstGridPointInDegrees,
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southPoleOnProjectionPlane,
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orientationOfTheGridInDegrees,
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LaDInDegrees,
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Dx,Dy,
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iScansNegatively,
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jScansPositively,
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jPointsAreConsecutive,
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alternativeRowScanning);
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nearest polar_stereographic(values,radius,Nx,Ny);
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meta latLonValues latlonvalues(values);
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alias latitudeLongitudeValues=latLonValues;
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meta latitudes latitudes(values,0);
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meta longitudes longitudes(values,0);
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meta distinctLatitudes latitudes(values,1);
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meta distinctLongitudes longitudes(values,1);
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