grid_tools  1.4.0
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pesg::hgrid_ak_rc Interface Reference

Private Member Functions

subroutine hgrid_ak_rc (lx, ly, nx, ny, A, K, plat, plon, pazi, delx, dely, xc, xcd, garea, ff)
 Use a and k as the parameters of an Extended Schmidt-transformed Gnomonic (ESG) mapping centered at (plat,plon) and twisted about this center by an azimuth angle of pazi counterclockwise (these angles in radians). More...
 

Detailed Description

Definition at line 45 of file pesg.f90.

Constructor & Destructor Documentation

subroutine pesg::hgrid_ak_rc::hgrid_ak_rc ( integer(spi), intent(in)  lx,
integer(spi), intent(in)  ly,
integer(spi), intent(in)  nx,
integer(spi), intent(in)  ny,
real(dp), intent(in)  A,
real(dp), intent(in)  K,
real(dp), intent(in)  plat,
real(dp), intent(in)  plon,
real(dp), intent(in)  pazi,
real(dp), intent(in)  delx,
real(dp), intent(in)  dely,
real(dp), dimension(3, lx:lx+nx ,ly:ly+ny ), intent(out)  xc,
real(dp), dimension(3,2,lx:lx+nx ,ly:ly+ny ), intent(out)  xcd,
real(dp), dimension( lx:lx+nx-1,ly:ly+ny-1), intent(out)  garea,
logical, intent(out)  ff 
)
private

Use a and k as the parameters of an Extended Schmidt-transformed Gnomonic (ESG) mapping centered at (plat,plon) and twisted about this center by an azimuth angle of pazi counterclockwise (these angles in radians).

Assume the radius of the earth is unity, and using the central mapping point as the coordinate origin, set up the grid with central x-spacing delx and y-spacing dely. The grid index location of the left-lower corner of the domain is (lx,ly) (typically both NEGATIVE). The numbers of the grid spaces in x and y directions are nx and ny. (Note that, for a centered rectangular grid lx and ly are negative and, in magnitude, half the values of nx and ny respectively.) Return the unit cartesian vectors xc of the grid points and their jacobian matrices xcd wrt the map coordinates, and return a rectangular array, garea, of dimensions nx-1 by ny-1, that contains the areas of each of the grid cells

If all goes well, return a lowered failure flag, ff=.false. . But if, for some reason, it is not possible to complete this task, return the raised failure flag, ff=.TRUE. .

Parameters
lxcenter-relative x grid index for left edge of the domain
lycenter-relative y grid index for lower edge of the domain
nxnumbers of the grid spaces in x
nynumbers of the grid spaces in y
aparameters of the ESG mapping centered at (plat,plon)
kparameters of the ESG mapping centered at (plat,plon)
platlatitude of the projection center of the mapping (radians)
plonlongitude of the projection center of the mapping (radians)
paziazimuth of orientation of mapping at its center
delxcentral x-spacing of the grid (in radians)
delycentral y-spacing of the grid (in radians)
xcEarth-centered unit cartesian 3-vectors at each grid point
xcdJacobian matrices, d(xc)/d(xm), at each grid point
garearectangular array of grid-cell areas (steradians)
fffailure flag
Author
R. J. Purser

Definition at line 1538 of file pesg.f90.


The documentation for this interface was generated from the following file: