SUBROUTINE UNGRIDB( NCOLS, NROWS, XORIG, YORIG, XCELL, YCELL, & NPTS, XLOC, YLOC, NU, CU ) INTEGER NCOLS, NROWS ! number of grid columns, rows REAL*8 XORIG, YORIG ! X,Y coords of LL grid corner REAL*8 XCELL, YCELL ! X,Y direction cell size INTEGER NPTS ! number of (point-source) locations REAL XLOC( NPTS ) ! X point coordinates REAL YLOC( NPTS ) ! Y point coordinates INTEGER NU( 4,NPTS ) ! single-indexed subscripts into grid REAL CU( 4,NPTS ) ! coefficients SUBROUTINE UNGRIDI( NCOLS, NROWS, XORIG, YORIG, XCELL, YCELL, & NPTS, XLOC, YLOC, NX ) INTEGER NCOLS, NROWS ! number of grid columns, rows REAL*8 XORIG, YORIG ! X,Y coords of LL grid corner REAL*8 XCELL, YCELL ! X,Y direction cell size INTEGER NPTS ! number of (point-source) locations REAL XLOC( NPTS ) ! X point coordinates REAL YLOC( NPTS ) ! Y point coordinates INTEGER NX( NPTS ) ! single-indexed subscripts into grid
{ <XLOC(S),YLOC(S)>, S=1, ..., NPTS }More detail on the computation of these coefficients, etc., is given in the section on BMATVEC().
UNGRIDI() computes "incidence matrix ungridding" indices for grid-to-grid transformation from a grid to the set of target (e.g., point source) locations as specified above, i.e., so that for a variable V(NCOLS*NROWS) single-indexed on the source grid,
VNEW(S) = V(NX(S)) is the value at { <XLOC(S),YLOC(S)>
See also subroutines
BMATVEC and BILIN, DMATVEC, PMATVEC, and SMATVECand programs
MTXBLEND, MTXBUILD, MTXCALC, MTXCPLE.
USE M3UTILIO
!! under construction !! (see BMATVEC)
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