mirror of https://github.com/ecmwf/eccodes.git
86 lines
3.4 KiB
Modula-2
86 lines
3.4 KiB
Modula-2
# (C) Copyright 2005- ECMWF.
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# TEMPLATE 3.20, Polar stereographic projection
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include "grib2/template.3.shape_of_the_earth.def"
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constant isGridded = true;
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# Nx - number of points along X-axis
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unsigned[4] 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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# Ny - number of points along Y-axis
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unsigned[4] Ny : dump;
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alias Nj = Ny;
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alias numberOfPointsAlongYAxis = Ny;
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alias numberOfPointsAlongAMeridian = Nj;
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alias geography.Ny=Ny;
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# La1 - latitude of first grid point
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signed[4] latitudeOfFirstGridPoint : edition_specific ;
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meta geography.latitudeOfFirstGridPointInDegrees scale(latitudeOfFirstGridPoint,oneConstant,grib2divider,truncateDegrees) : dump;
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alias La1 = latitudeOfFirstGridPoint;
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# Lo1 - longitude of first grid point
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unsigned[4] longitudeOfFirstGridPoint : edition_specific;
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meta geography.longitudeOfFirstGridPointInDegrees scale(longitudeOfFirstGridPoint,oneConstant,grib2divider,truncateDegrees) : dump;
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alias Lo1 = longitudeOfFirstGridPoint;
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# Resolution and component flag
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flags[1] resolutionAndComponentFlags 'grib2/tables/[tablesVersion]/3.3.table' : dump;
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# LaD - Latitude where Dx and Dy are specified
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signed[4] LaD : edition_specific;
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alias latitudeWhereDxAndDyAreSpecified=LaD;
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meta geography.LaDInDegrees scale(LaD,oneConstant,grib2divider,truncateDegrees) : dump;
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alias latitudeWhereDxAndDyAreSpecifiedInDegrees=LaDInDegrees;
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# LoV - orientation of the grid
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# LoV is the longitude value of the meridian which is parallel to the y-axis (or columns of the grid)
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# along which latitude increases as the y-coordinate increases
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signed[4] orientationOfTheGrid : edition_specific;
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alias LoV = orientationOfTheGrid ;
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meta geography.orientationOfTheGridInDegrees scale(orientationOfTheGrid,oneConstant,grib2divider,truncateDegrees) : dump;
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# Dx - X-direction grid length
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# Grid length is in units of 10-3 m at the latitude specified by LaD
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unsigned[4] Dx : edition_specific;
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meta geography.DxInMetres scale(Dx,one,thousand,truncateDegrees) : dump;
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alias xDirectionGridLength=Dx;
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# Dy - Y-direction grid length
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# Grid length is in units of 10-3 m at the latitude specified by LaD
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unsigned[4] Dy : edition_specific;
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meta geography.DyInMetres scale(Dy,one,thousand,truncateDegrees) : dump;
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alias yDirectionGridLength=Dy;
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# Projection centre flag
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flags[1] projectionCentreFlag 'grib2/tables/[tablesVersion]/3.5.table' : dump;
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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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include "grib2/template.3.scanning_mode.def"
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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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DxInMetres,DyInMetres,
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iScansNegatively, jScansPositively,
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jPointsAreConsecutive, 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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