ipxetas.F90 File Reference

Expand or contract eta grids using linear interpolation. More...

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Functions/Subroutines
subroutine	ipxetas (idir, igdtnumi, igdtlen, igdtmpli, npts_input, bitmap_input, data_input, igdtnumo, igdtmplo, npts_output, bitmap_output, data_output, iret)
	Expand or contract eta grids using linear interpolation.

Detailed Description

Expand or contract eta grids using linear interpolation.

Author

Iredell

Date

96-04-10

Definition in file ipxetas.F90.

Function/Subroutine Documentation

ipxetas()

subroutine ipxetas	(	integer, intent(in)	idir,
		integer, intent(in)	igdtnumi,
		integer, intent(in)	igdtlen,
		integer, dimension(igdtlen), intent(in)	igdtmpli,
		integer, intent(in)	npts_input,
		logical(kind=1), dimension(npts_input), intent(in)	bitmap_input,
		real, dimension(npts_input), intent(in)	data_input,
		integer, intent(out)	igdtnumo,
		integer, dimension(igdtlen), intent(out)	igdtmplo,
		integer, intent(in)	npts_output,
		logical(kind=1), dimension(npts_output), intent(out)	bitmap_output,
		real, dimension(npts_output), intent(out)	data_output,
		integer, intent(out)	iret
	)

Expand or contract eta grids using linear interpolation.

This subprogram transforms between the staggered eta grids as used in the eta model and for native grid transmission and their full expansion as used for general interpolation and graphics. The eta grids are rotated latitude-longitude grids staggered as defined by the arakawa e-grid, that is with mass data points alternating with wind data points.

This is similar to:

• ipxwafs2() which uses linear interpolation and accounts for
• bitmapped data.
• ipxwafs2() which uses neighbor interpolation and accounts for
• bitmapped data.

Program History Log

Date	Programmer	Comments
96-04-10	Iredell	Initial
2015-07-14	Gayno	Make grib 2 compliant. Replace 4-pt interpolation with call to ipolates.
2022-11-09	Engle	Made ibi and ibo scalars.

Parameters

[in]	idir	integer transform option. 0 to expand staggered fields to full fields -1 to contract full mass fields to staggered fields -2 to contract full wind fields to staggered fields
[in]	igdtnumi	integer grid definition template number - input grid. Corresponds to the gfldigdtnum component of the ncep g2 library gridmod data structure. Must be = 1 (for a rotated lat/lon grid.)
[in]	igdtlen	integer number of elements of the grid definition template array - same for input and output grids (=22) which are both rotated lat/lon grids. corresponds to the gfldigdtlen component of the ncep g2 library gridmod data structure.
[in]	igdtmpli	integer (igdtlen) grid definition template array - input grid. Corresponds to the gfldigdtmpl component of the ncep g2 library gridmod data structure (section 3 info): 1 shape of earth, octet 15 2 scale factor of spherical earth radius, octet 16 3 scaled value of radius of spherical earth, octets 17-20 4 scale factor of major axis of elliptical earth, octet 21 5 scaled value of major axis of elliptical earth, octets 22-25 6 scale factor of minor axis of elliptical earth, octet 26 7 scaled value of minor axis of elliptical earth, octets 27-30 8 number of points along a parallel, octs 31-34 9 number of points along a meridian, octs 35-38 10 basic angle of initial production domain, octets 39-42 11 subdivisions of basic angle, octets 43-46 12 latitude of first grid point, octets 47-50 13 longitude of first grid point, octets 51-54 14 resolution and component flags, octet 55 15 latitude of last grid point, octets 56-59 16 longitude of last grid point, octets 60-63 17 i-direction increment, octets 64-67 18 j-direction increment, octets 68-71 19 scanning mode, octet 72 20 latitude of southern pole of projection, octets 73-76 21 longitude of southern pole of projection, octets 77-80 22 angle of rotation of projection, octs 81-84
[in]	npts_input	integer number points input grid
[in]	bitmap_input	logical (npts_input) input grid bitmap
[in]	data_input	real (npts_input) input grid data
[out]	igdtnumo	integer grid definition template number - output grid. Corresponds to the gfldigdtnum component of the ncep g2 library gridmod data structure. Same as igdtnumi (=1 for a rotated lat/lon grid).
[out]	igdtmplo	integer (igdtlen) grid definition template array - output grid. Corresponds to the gfldigdtmpl component of the ncep g2 library gridmod data structure. Array definitions same as "igdtmpli".
[out]	npts_output	integer number points output grid. the j-dimension of the input and output grids are the same. When going from a staggered to a full grid the i-dimension increases to idim*2-1. When going from full to staggered the i-dimension decreases to (idim+1)/2.
[out]	bitmap_output	logical (npts_outut) output grid bitmap
[out]	data_output	real (npts_output) output grid data
[out]	iret	integer return code 0 successful transformation non-0 invalid grid specs or problem in ipolates().

Definition at line 90 of file ipxetas.F90.