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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include "im2interpdef.h"
include <math/iminterp.h>
# MRIEVAL -- Procedure to evaluate the 2D interpolant at a given value
# of x and y. MRIEVAL allows the interpolation of a few interpolated
# points without the computing time and storage required for the
# sequential version. The routine assumes that 1 <= x <= nxpix and
# 1 <= y <= nypix.
real procedure mrieval (x, y, datain, nxpix, nypix, len_datain, interp_type)
real x[ARB] # x value
real y[ARB] # y value
real datain[len_datain,ARB] # data array
int nxpix # number of x data points
int nypix # number of y data points
int len_datain # row length of datain
int interp_type # interpolant type
int nx, ny, nterms, row_length
int xindex, yindex, first_row, last_row
int kx, ky
int i, j
pointer tmp
real coeff[SPLPTS+3,SPLPTS+3]
real hold21, hold12, hold22
real sx, sy, tx, ty
real xval, yval, value
errchk malloc, calloc, mfree
begin
switch (interp_type) {
case II_BINEAREST:
return (datain[int (x[1]+0.5), int (y[1]+0.5)])
case II_BILINEAR:
nx = x[1]
sx = x[1] - nx
tx = 1. - sx
ny = y[1]
sy = y[1] - ny
ty = 1. - sy
# protect against the case where x = nxpix and/or y = nypix
if (nx >= nxpix)
hold21 = 2. * datain[nx,ny] - datain[nx-1,ny]
else
hold21 = datain[nx+1,ny]
if (ny >= nypix)
hold12 = 2. * datain[nx,ny] - datain[nx,ny-1]
else
hold12 = datain[nx,ny+1]
if (nx >= nxpix && ny >= nypix)
hold22 = 2. * hold21 - (2. * datain[nx,ny-1] -
datain[nx-1,ny-1])
else if (nx >= nxpix)
hold22 = 2. * hold12 - datain[nx-1,ny+1]
else if (ny >= nypix)
hold22 = 2. * hold21 - datain[nx+1,ny-1]
else
hold22 = datain[nx+1,ny+1]
# evaluate the interpolant
value = tx * ty * datain[nx,ny] + sx * ty * hold21 +
sy * tx * hold12 + sx * sy * hold22
return (value)
case II_BIDRIZZLE:
call ii_bidriz1 (datain, 0, len_datain, x, y, value, 1, BADVAL)
return (value)
case II_BIPOLY3:
row_length = SPLPTS + 3
nterms = 4
nx = x[1]
ny = y[1]
# major problem is that near the edge the interior polynomial
# must be defined
# use boundary projection to extend the data rows
yindex = 1
for (j = ny - 1; j <= ny + 2; j = j + 1) {
# check that the data row is defined
if (j >= 1 && j <= nypix) {
# extend the rows
xindex = 1
for (i = nx - 1; i <= nx + 2; i = i + 1) {
if (i < 1)
coeff[xindex,yindex] = 2. * datain[1,j] -
datain[2-i,j]
else if (i > nxpix)
coeff[xindex,yindex] = 2. * datain[nxpix,j] -
datain[2*nxpix-i,j]
else
coeff[xindex,yindex] = datain[i,j]
xindex = xindex + 1
}
} else if (j == (ny + 2)) {
# extend the rows
xindex = 1
for (i = nx - 1; i <= nx + 2; i = i + 1) {
if (i < 1)
coeff[xindex,yindex] = 2. * datain[1,nypix-2] -
datain[2-i,nypix-2]
else if (i > nxpix)
coeff[xindex,yindex] = 2. * datain[nxpix,nypix-2] -
datain[2*nxpix-i,nypix-2]
else
coeff[xindex,yindex] = datain[i,nypix-2]
xindex = xindex + 1
}
}
yindex = yindex + 1
}
# project columns
first_row = max (1, 3 - ny)
if (first_row > 1) {
for (j = 1; j < first_row; j = j + 1)
call awsur (coeff[1, first_row], coeff[1, 2*first_row-j],
coeff[1,j], nterms, 2., -1.)
}
last_row = min (nterms, nypix - ny + 2)
if (last_row < nterms) {
for (j = last_row + 1; j <= nterms - 1; j = j + 1)
call awsur (coeff[1,last_row], coeff[1,2*last_row-j],
coeff[1,j], nterms, 2., -1.)
if (last_row == 2)
call awsur (coeff[1,last_row], coeff[1,4], coeff[1,4],
nterms, 2., -1.)
else
call awsur (coeff[1,last_row], coeff[1,2*last_row-4],
coeff[1,4], nterms, 2., -1.)
}
# center the x value and call evaluation routine
xval = 2 + (x[1] - nx)
yval = 2 + (y[1] - ny)
call ii_bipoly3 (coeff, 0, row_length, xval, yval, value, 1)
return (value)
case II_BIPOLY5:
row_length = SPLPTS + 3
nterms = 6
nx = x[1]
ny = y[1]
# major problem is to define interior polynomial near the edge
# loop over the rows of data
yindex = 1
for (j = ny - 2; j <= ny + 3; j = j + 1) {
# select the rows containing data
if (j >= 1 && j <= nypix) {
# extend the rows
xindex = 1
for (i = nx - 2; i <= nx + 3; i = i + 1) {
if (i < 1)
coeff[xindex,yindex] = 2. * datain[1,j] -
datain[2-i,j]
else if (i > nxpix)
coeff[xindex,yindex] = 2. * datain[nxpix,j] -
datain[2*nxpix-i,j]
else
coeff[xindex,yindex] = datain[i,j]
xindex = xindex + 1
}
} else if (j == (ny + 3)) {
# extend the rows
xindex = 1
for (i = nx - 2; i <= nx + 3; i = i + 1) {
if (i < 1)
coeff[xindex,yindex] = 2. * datain[1,nypix-3] -
datain[2-i,nypix-3]
else if (i > nxpix)
coeff[xindex,yindex] = 2. * datain[nxpix,nypix-3] -
datain[2*nxpix-i,nypix-3]
else
coeff[xindex,yindex] = datain[i,nypix-3]
xindex = xindex + 1
}
}
yindex = yindex + 1
}
# project columns
first_row = max (1, 4 - ny)
if (first_row > 1) {
for (j = 1; j < first_row; j = j + 1)
call awsur (coeff[1,first_row], coeff[1,2*first_row-j],
coeff[1,j], nterms, 2., -1.)
}
last_row = min (nterms, nypix - ny + 3)
if (last_row < nterms) {
for (j = last_row + 1; j <= nterms - 1; j = j + 1)
call awsur (coeff[1,last_row], coeff[1,2*last_row-j],
coeff[1,j], nterms, 2., -1.)
if (last_row == 3)
call awsur (coeff[1,last_row], coeff[1,6], coeff[1,6],
nterms, 2., -1.)
else
call awsur (coeff[1,last_row], coeff[1,2*last_row-6],
coeff[1,6], nterms, 2., -1.)
}
# call evaluation routine
xval = 3 + (x[1] - nx)
yval = 3 + (y[1] - ny)
call ii_bipoly5 (coeff, 0, row_length, xval, yval, value, 1)
return (value)
case II_BISPLINE3:
row_length = SPLPTS + 3
nx = x[1]
ny = y[1]
# allocate space for temporary array and 0 file
call calloc (tmp, row_length * row_length, TY_REAL)
ky = 0
# maximum number of points used in each direction is SPLPTS
for (j = ny - SPLPTS/2 + 1; j <= ny + SPLPTS/2; j = j + 1) {
if (j < 1 || j > nypix)
;
else {
ky = ky + 1
if (ky == 1)
yindex = ny - j + 1
kx = 0
for (i = nx - SPLPTS/2 + 1; i <= nx + SPLPTS/2; i = i + 1) {
if (i < 1 || i > nxpix)
;
else {
kx = kx + 1
if (kx == 1)
xindex = nx - i + 1
coeff[kx+1,ky+1] = datain[i,j]
}
}
coeff[1,ky+1] = 0.
coeff[kx+2,ky+1] = 0.
coeff[kx+3,ky+1] = 0.
}
}
# zero out 1st and last 2 rows
call amovkr (0., coeff[1,1], kx+3)
call amovkr (0., coeff[1,ky+2], kx+3)
call amovkr (0., coeff[1,ky+3],kx+3)
# calculate the spline coefficients
call ii_spline2d (coeff, Memr[tmp], kx, ky+2, row_length,
row_length)
call ii_spline2d (Memr[tmp], coeff, ky, kx+2, row_length,
row_length)
# evaluate spline
xval = xindex + 1 + (x[1] - nx)
yval = yindex + 1 + (y[1] - ny)
call ii_bispline3 (coeff, 0, row_length, xval, yval, value, 1)
# free space
call mfree (tmp, TY_REAL)
return (value)
case II_BISINC, II_BILSINC:
call ii_bisinc (datain, 0, len_datain, nypix, x, y, value, 1,
NSINC, DX, DY)
return (value)
}
end
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