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include <gset.h>
include <smw.h>
include "identify.h"
# ID_CENTER -- Locate the center of a feature.
double procedure id_center (id, x, n, width, type, interactive)
pointer id # ID pointer
double x[n] # Initial guess
int n # Number of features
real width # Feature width
int type # Feature type
int interactive # Interactive?
int np1
real value
real center1d()
double smw_c1trand()
begin
switch (type) {
case EMISSION, ABSORPTION:
np1 = NP1(ID_SH(id)) - 1
value = smw_c1trand (ID_PL(id), x[1]) - np1
value = center1d (value, IMDATA(id,1), ID_NPTS(id),
width, type, ID_CRADIUS(id), ID_THRESHOLD(id))
if (IS_INDEF(value))
return (INDEFD)
else
return (smw_c1trand (ID_LP(id), double(value+np1)))
case GEMISSION, GABSORPTION:
iferr (call id_gcenter (id, x, n, INDEF, INDEF, INDEF, INDEF,
width, type, interactive))
return (INDEFD)
return (x[1])
}
end
# ID_GCENTER -- Locate the center of a feature.
procedure id_gcenter (id, x, ng, xa, ya, xb, yb, width, type, interactive)
pointer id # ID pointer
double x[ng] # Initial guess
int ng # Number of features
real xa, ya, xb, yb # Background points
real width # Feature width
int type # Feature type
int interactive # Draw gaussian fit?
int i, np1, x1, x2
real ag, bg, pix, w, y
pointer sp, xr, xg, yg, sg, gp
bool fp_equalr()
real id_model()
double smw_c1trand(), id_fitpt()
errchk gcenter1d
begin
call smark (sp)
call salloc (xr, ng, TY_REAL)
call salloc (xg, ng, TY_REAL)
call salloc (yg, ng, TY_REAL)
call salloc (sg, ng, TY_REAL)
np1 = NP1(ID_SH(id)) - 1
# Compute background in logical units.
if (IS_INDEF(xa) || IS_INDEF(ya) || IS_INDEF(xb) || IS_INDEF(yb)) {
ag = INDEF
bg = INDEF
} else {
ag = smw_c1trand (ID_PL(id), double(xa)) - np1
bg = smw_c1trand (ID_PL(id), double(xb)) - np1
if (!fp_equalr (ag, bg)) {
bg = (yb - ya) / (bg - ag)
ag = ya - bg * ag
} else {
ag = INDEF
bg = INDEF
}
}
do i = 1, ng
Memr[xr+i-1] = smw_c1trand (ID_PL(id), x[i]) - np1
call gcenter1d (Memr[xr], ng, IMDATA(id,1), ID_NPTS(id),
width, type, ID_CRADIUS(id), ID_THRESHOLD(id),
x1, x2, Memr[xg], Memr[yg], Memr[sg], ag, bg)
do i = 1, ng
x[i] = smw_c1trand (ID_LP(id), double(Memr[xg+i-1]+np1))
if (interactive == YES) {
gp = ID_GP(id)
call gseti (gp, G_PLTYPE, 2)
call gseti (gp, G_PLCOLOR, 2)
pix = x1
w = id_fitpt (id, smw_c1trand (ID_LP(id), double (pix+np1)))
y = id_model (pix, Memr[xg], Memr[yg], Memr[sg], ng) + ag +
bg * pix
call gamove (gp, w, y)
for (pix = x1; pix <= x2; pix = pix + .1) {
w = id_fitpt (id, smw_c1trand (ID_LP(id), double (pix+np1)))
y = id_model (pix, Memr[xg], Memr[yg], Memr[sg], ng) +
ag + bg * pix
call gadraw (gp, w, y)
}
call gseti (gp, G_PLTYPE, 3)
call gseti (gp, G_PLCOLOR, 3)
pix = x1
w = id_fitpt (id, smw_c1trand (ID_LP(id), double (pix+np1)))
y = ag + bg * pix
call gamove (gp, w, y)
pix = x2
w = id_fitpt (id, smw_c1trand (ID_LP(id), double (pix+np1)))
y = ag + bg * pix
call gadraw (gp, w, y)
call gseti (gp, G_PLTYPE, 1)
call gseti (gp, G_PLCOLOR, 1)
call gflush (gp)
}
call sfree (sp)
end
define MIN_WIDTH 3. # Minimum centering width
# GCENTER1D -- Locate the center of a one dimensional feature by guassian fit.
# A value of INDEF is returned in the centering fails for any reason.
# This procedure just sets up the data and adjusts for emission or
# absorption features. The actual centering is done by GFIT.
# If width <= 1 return the nearest minima or maxima.
procedure gcenter1d (x, ng, data, npts, width, type, radius, threshold,
x1, x2, xg, yg, sg, ag, bg)
real x[ng] # Initial guess
int ng # Number of gaussians
real data[npts] # Data points
int npts # Number of data points
real width # Feature width
int type # Feature type
real radius # Centering radius
real threshold # Minimum range in feature
int x1, x2 # Fitting region
real xg[ng], yg[ng], sg[ng], ag, bg # Gaussian parameters
int i, nx, xa, xb
real a, b, c, d, rad, wid, ya, yb, chisq
pointer xfit
errchk id_mr_dofit
begin
# Check starting values.
do i = 1, ng
if (IS_INDEF(x[i]) || (x[i] < 1) || (x[i] > npts))
call error (1, "Invalid starting values")
# Set minimum width and error radius. The minimum in the error radius
# is for defining the data window. The user error radius is used to
# check for an error in the derived center at the end of the centering.
wid = max (width, MIN_WIDTH)
rad = max (2., radius)
# Determine the pixel value range around the initial center, including
# the width and error radius buffer. Check for a minimum range.
call alimr (x, ng, c, d)
x1 = max (1., c - wid / 2 - rad - wid)
x2 = min (real (npts), d + wid / 2 + rad + wid + 1)
nx = x2 - x1 + 1
call alimr (data[x1], nx, a, b)
if (b - a < threshold)
call error (1, "Data range below threshold")
# Allocate memory for the continuum subtracted data vector. The X
# range is just large enough to include the error radius and the
# half width.
x1 = max (1., c - wid / 2 - rad)
x2 = min (real (npts), d + wid / 2 + rad + 1)
nx = x2 - x1 + 1
# Make the centering data positive, subtract the continuum, and
# apply a threshold to eliminate noise spikes.
xa = nint(c)
ya = data[xa]
xb = nint(d)
yb = data[xb]
switch (type) {
case GEMISSION:
for (i = xa; i >= x1; i=i-1)
if (data[i] < ya) {
xa = i
ya = data[i]
}
for (i = xb; i <= x2; i=i+1)
if (data[i] < yb) {
xb = i
yb = data[i]
}
case GABSORPTION:
for (i = xa; i >= x1; i=i-1)
if (data[i] > ya) {
xa = i
ya = data[i]
}
for (i = xb; i <= x2; i=i+1)
if (data[i] > yb) {
xb = i
yb = data[i]
}
default:
call error (0, "Unknown feature type")
}
# Set initial gaussian parameters.
if (IS_INDEF(ag) || IS_INDEF(bg)) {
if (xa == xb)
call error (1, "Can't determine background")
bg = (yb-ya) / (xb-xa)
ag = ya - bg * xa
}
do i = 1, ng {
xg[i] = x[i]
yg[i] = data[nint(x[i])] - ag - bg * x[i]
sg[i] = width / 6.
}
# Determine the center.
call malloc (xfit, nx, TY_REAL)
do i = x1, x2
Memr[xfit+i-x1] = i
call id_mr_dofit (0, 3, 3, Memr[xfit], data[x1], nx,
ag, bg, xg, yg, sg, ng, chisq)
# Check user centering error radius.
do i = 1, ng {
if (!IS_INDEF(xg[i])) {
if (abs (x[i] - xg[i]) > radius)
call error (2, "Error radius exceeded")
}
}
# Free memory and return the center position.
call mfree (xfit, TY_REAL)
end
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