# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.

include <math/gsurfit.h>
$if (datatype == r)
include "gsurfitdef.h"
$else
include "dgsurfitdef.h"
$endif

# GSACPTS -- Procedure to add a set of points to the normal equations.
# The inner products of the basis functions are calculated and
# accumulated into the GS_NCOEFF(sf) ** 2 matrix MATRIX.
# The main diagonal of the matrix is stored in the first row of
# MATRIX followed by the remaining non-zero diagonals.
# The inner product
# of the basis functions and the data ordinates are stored in the
# NCOEFF(sf)-vector VECTOR.

$if (datatype == r)
procedure gsacpts (sf, x, y, z, w, npts, wtflag)
$else
procedure dgsacpts (sf, x, y, z, w, npts, wtflag)
$endif

pointer	sf		# surface descriptor
PIXEL	x[npts]		# array of x values
PIXEL	y[npts]		# array of y values
PIXEL	z[npts]		# data array
PIXEL	w[npts]		# array of weights
int	npts		# number of data points
int	wtflag		# type of weighting

bool	refsub
int	i, ii, j, jj, k, l, ll
int	maxorder, xorder, xxorder, ntimes
pointer	sp, vzptr, vindex, mzptr, mindex, bxptr, bbxptr, byptr, bbyptr
pointer	x1, y1, z1, byw, bw

PIXEL	adot$t()

begin
	# increment the number of points
	GS_NPTS(sf) = GS_NPTS(sf) + npts

	# remove basis functions calculated by any previous gsrefit call
	if (GS_XBASIS(sf) != NULL || GS_YBASIS(sf) != NULL) {

	    $if (datatype == r)
	    if (GS_XBASIS(sf) != NULL)
	        call mfree (GS_XBASIS(sf), TY_REAL)
	    GS_XBASIS(sf) = NULL
	    if (GS_YBASIS(sf) != NULL)
	        call mfree (GS_YBASIS(sf), TY_REAL)
	    GS_YBASIS(sf) = NULL
	    if (GS_WZ(sf) != NULL)
	        call mfree (GS_WZ(sf), TY_REAL)
	    GS_WZ(sf) = NULL
	    $else
	    if (GS_XBASIS(sf) != NULL)
	        call mfree (GS_XBASIS(sf), TY_DOUBLE)
	    GS_XBASIS(sf) = NULL
	    if (GS_YBASIS(sf) != NULL)
	        call mfree (GS_YBASIS(sf), TY_DOUBLE)
	    GS_YBASIS(sf) = NULL
	    if (GS_WZ(sf) != NULL)
	        call mfree (GS_WZ(sf), TY_DOUBLE)
	    GS_WZ(sf) = NULL
	    $endif
	}

	# calculate weights
	switch (wtflag) {
	case WTS_UNIFORM:
	    $if (datatype == r)
	    call amovkr (1., w, npts)
	    $else
	    call amovkd (1.0d0, w, npts)
	    $endif
	case WTS_SPACING:
	    if (npts == 1)
		$if (datatype == r)
		w[1] = 1.
		$else
		w[1] = 1.0d0
		$endif
	    else
	        w[1] = abs (x[2] - x[1])
	    do i = 2, npts - 1
		w[i] = abs (x[i+1] - x[i-1])
	    if (npts == 1)
		$if (datatype == r)
		w[npts] = 1.
		$else
		w[npts] = 1.0d0
		$endif
	    else
	        w[npts] = abs (x[npts] - x[npts-1])
	case WTS_USER:
	    # user supplied weights
	default:
	    $if (datatype == r)
	    call amovkr (1., w, npts)
	    $else
	    call amovkd (1.0d0, w, npts)
	    $endif
	}


	# allocate space for the basis functions
	call smark (sp)
	call salloc (GS_XBASIS(sf), npts * GS_XORDER(sf), TY_PIXEL)
	call salloc (GS_YBASIS(sf), npts * GS_YORDER(sf), TY_PIXEL)

	# subtract reference value
	refsub = !(IS_INDEF(GS_XREF(sf)) || IS_INDEF(GS_YREF(sf)) ||
	    IS_INDEF(GS_ZREF(sf)))
	if (refsub) {
	    call salloc (x1, npts, TY_PIXEL)
	    call salloc (y1, npts, TY_PIXEL)
	    call salloc (z1, npts, TY_PIXEL)
	    call asubk$t (x, GS_XREF(sf), Mem$t[x1], npts)
	    call asubk$t (y, GS_YREF(sf), Mem$t[y1], npts)
	    call asubk$t (z, GS_ZREF(sf), Mem$t[z1], npts)
	}

	# calculate the non-zero basis functions
	switch (GS_TYPE(sf)) {
	case GS_LEGENDRE:
	    if (refsub) {
		call $tgs_bleg (Mem$t[x1], npts, GS_XORDER(sf), GS_XMAXMIN(sf),
		    GS_XRANGE(sf), XBASIS(GS_XBASIS(sf)))
		call $tgs_bleg (Mem$t[y1], npts, GS_YORDER(sf), GS_YMAXMIN(sf),
		    GS_YRANGE(sf), YBASIS(GS_YBASIS(sf)))
	    } else {
		call $tgs_bleg (x, npts, GS_XORDER(sf), GS_XMAXMIN(sf),
		    GS_XRANGE(sf), XBASIS(GS_XBASIS(sf)))
		call $tgs_bleg (y, npts, GS_YORDER(sf), GS_YMAXMIN(sf),
		    GS_YRANGE(sf), YBASIS(GS_YBASIS(sf)))
	    }
	case GS_CHEBYSHEV:
	    if (refsub) {
		call $tgs_bcheb (Mem$t[x1], npts, GS_XORDER(sf), GS_XMAXMIN(sf),
		    GS_XRANGE(sf), XBASIS(GS_XBASIS(sf)))
		call $tgs_bcheb (Mem$t[y1], npts, GS_YORDER(sf), GS_YMAXMIN(sf),
		    GS_YRANGE(sf), YBASIS(GS_YBASIS(sf)))
	    } else {
		call $tgs_bcheb (x, npts, GS_XORDER(sf), GS_XMAXMIN(sf),
		    GS_XRANGE(sf), XBASIS(GS_XBASIS(sf)))
		call $tgs_bcheb (y, npts, GS_YORDER(sf), GS_YMAXMIN(sf),
		    GS_YRANGE(sf), YBASIS(GS_YBASIS(sf)))
	    }
	case GS_POLYNOMIAL:
	    if (refsub) {
		call $tgs_bpol (Mem$t[x1], npts, GS_XORDER(sf), GS_XMAXMIN(sf),
		    GS_XRANGE(sf), XBASIS(GS_XBASIS(sf)))
		call $tgs_bpol (Mem$t[y1], npts, GS_YORDER(sf), GS_YMAXMIN(sf),
		    GS_YRANGE(sf), YBASIS(GS_YBASIS(sf)))
	    } else {
		call $tgs_bpol (x, npts, GS_XORDER(sf), GS_XMAXMIN(sf),
		    GS_XRANGE(sf), XBASIS(GS_XBASIS(sf)))
		call $tgs_bpol (y, npts, GS_YORDER(sf), GS_YMAXMIN(sf),
		    GS_YRANGE(sf), YBASIS(GS_YBASIS(sf)))
	    }
	default:
	    call error (0, "GSACCUM: Illegal curve type.")
	}

	# allocate temporary storage space for matrix accumulation
	$if (datatype == r)
	call salloc (byw, npts, TY_REAL)
	call salloc (bw, npts, TY_REAL)
	$else
	call salloc (byw, npts, TY_DOUBLE)
	call salloc (bw, npts, TY_DOUBLE)
	$endif

	# one index the pointers
	vzptr = GS_VECTOR(sf) - 1
	mzptr = GS_MATRIX(sf)
	bxptr = GS_XBASIS(sf)
	byptr = GS_YBASIS(sf)

	switch (GS_TYPE(sf)) {

	case GS_LEGENDRE, GS_CHEBYSHEV, GS_POLYNOMIAL:

	    maxorder = max (GS_XORDER(sf) + 1, GS_YORDER(sf) + 1)
	    xorder = GS_XORDER(sf)
	    ntimes = 0

	    do l = 1, GS_YORDER(sf) {

		call amul$t (w, YBASIS(byptr), Mem$t[byw], npts)
	        bxptr = GS_XBASIS(sf)
	        do k = 1, xorder {
	            call amul$t (Mem$t[byw], XBASIS(bxptr), Mem$t[bw], npts) 
		    vindex = vzptr + k
	            VECTOR(vindex) = VECTOR(vindex) + adot$t (Mem$t[bw], z,
		        npts)
		    bbyptr = byptr
	            bbxptr = bxptr
		    xxorder = xorder
		    jj = k
		    ll = l
	            ii = 0
		    do j = k + ntimes, GS_NCOEFF(sf) {
		        mindex = mzptr + ii
		        do i = 1, npts
		            MATRIX(mindex) = MATRIX(mindex) + Mem$t[bw+i-1] *
				XBASIS(bbxptr+i-1) * YBASIS(bbyptr+i-1)	
			if (mod (jj, xxorder) == 0) {
			    jj = 1
			    ll = ll + 1
			    bbxptr = GS_XBASIS(sf)
			    bbyptr = bbyptr + npts
			    switch (GS_XTERMS(sf)) {
			    case GS_XNONE:
				xxorder = 1
			    case GS_XHALF:
				if ((ll + GS_XORDER(sf)) > maxorder)
		    		    xxorder = xxorder - 1
			    default:
				;
			    }
			} else {
			    jj = jj + 1
			    bbxptr = bbxptr + npts
			}
		        ii = ii + 1
		    }
		    mzptr = mzptr + GS_NCOEFF(sf)
		    bxptr = bxptr + npts
	        }

		vzptr = vzptr + xorder
		ntimes = ntimes + xorder
		switch (GS_XTERMS(sf)) {
		case GS_XNONE:
		    xorder = 1
		case GS_XHALF:
		    if ((l + GS_XORDER(sf) + 1) > maxorder)
		        xorder = xorder - 1
		default:
		    ;
		}
		byptr = byptr + npts
	    }

	default:
	    call error (0, "GSACCUM: Unknown curve type.")
	}

	# release the space
	call sfree (sp)
	GS_XBASIS(sf) = NULL
	GS_YBASIS(sf) = NULL
end