1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
|
include <error.h>
include <mach.h>
include <gset.h>
include "rvflags.h"
include "rvpackage.h"
define SQ2PI 2.5066283
# RV_LINEFIT - Fit a gaussian to a line between two specified endpoints.
procedure rv_linefit (rv, x1, x2, stdlam, which)
pointer rv #I RV struct pointer
real x1 #I left edge of fit
real x2 #I right edge of fit
real stdlam #I standard wavelength
int which #I which spectrum to fit
int ix1, ix2
begin
if (which == OBJECT_SPECTRUM) { # Fit at the top
if (RV_DCFLAG(rv) != -1) {
x1 = (log10(x1) - RV_OW0(rv)) / RV_OWPC(rv) + 1
x2 = (log10(x2) - RV_OW0(rv)) / RV_OWPC(rv) + 1
}
ix1 = int (x1 + 0.5) # round off
ix2 = int (x2 + 0.5)
if (OBJCONT(rv) == NO) {
call rv_gfit (rv, RV_GP(rv), RV_OW0(rv), RV_OWPC(rv),
ix1, ix2, OBJPIXX(rv,1), OBJPIXY(rv,1),
RV_NPTS(rv), stdlam, TOP)
} else {
call rv_gfit (rv, RV_GP(rv), RV_OW0(rv), RV_OWPC(rv),
ix1, ix2, OBJPIXX(rv,1), OCONT_DATA(rv,1),
RV_NPTS(rv), stdlam, TOP)
}
} else {
if (RV_DCFLAG(rv) != -1) {
x1 = (log10(x1) - RV_RW0(rv)) / RV_RWPC(rv) + 1
x2 = (log10(x2) - RV_RW0(rv)) / RV_RWPC(rv) + 1
}
ix1 = int (x1 + 0.5) # round off
ix2 = int (x2 + 0.5)
if (REFCONT(rv) == NO) {
call rv_gfit (rv, RV_GP(rv), RV_RW0(rv), RV_RWPC(rv),
ix1, ix2, REFPIXX(rv,1), REFPIXY(rv,1),
RV_RNPTS(rv), stdlam, BOTTOM)
} else {
call rv_gfit (rv, RV_GP(rv), RV_RW0(rv), RV_RWPC(rv),
ix1, ix2, REFPIXX(rv,1), RCONT_DATA(rv,1),
RV_RNPTS(rv), stdlam, BOTTOM)
}
}
end
# RV_GFIT -- Fit a Gaussian to a spectral line and output it's velocity
# based on a standard wavelength.
procedure rv_gfit (rv, gp, w0, wpc, left, right, pixx, pixy, ndata, lam,
where)
pointer rv #I RV task structure
pointer gp #I GIO pointer
real w0, wpc #I Dispsersion params
int left, right #I Fitting region endpoints
real pixx[ARB] #I Spectrum data
real pixy[ARB] #I Spectrum data
int ndata #I Number of points
real lam #I standard line wavelength
int where #I where to plot the line
int i, j, npts, nlines
real w, wyc, wx, wy, wx2, wy2, wx1, wy1, a[5]
real x1, x2, y1, y2, range, peakx, vel, shift
real slope, height, flux, cont, sigma, eqw, scale, chisq
bool fit
pointer sp, x, y, z
double dex(), rv_shift2vel()
real model(), rv_maxpix(), rv_minpix()
bool fp_equalr()
errchk dofit
define done_ 99
begin
# Determine number of points to fit.
npts = right - left + 1
if (npts < 3) {
call eprintf ("At least 3 points are required\n")
return
}
# Allocate space for the points to be fit.
call smark (sp)
call salloc (x, npts, TY_REAL)
call salloc (y, npts, TY_REAL)
call salloc (z, npts, TY_REAL)
# Scale the data.
scale = 0.
do i = 1, npts {
Memr[x+i-1] = dex (pixx[left+i-1])
Memr[y+i-1] = pixy[left+i-1]
scale = max (scale, abs (Memr[y+i-1]))
}
if (fp_equalr(scale,0.0))
scale = 1.0
call adivkr (Memr[y], scale, Memr[y], npts)
# Setup initial estimates.
wx1 = dex (pixx[left])
wx2 = dex (pixx[right])
wy1 = pixy[left]
wy2 = pixy[right]
slope = (wy2-wy1) / (wx2-wx1) / scale
wyc = wy1 / scale - slope * wx1
wx = 0
do i = 0, npts-1 {
w = Memr[x+i]
wy = Memr[y+i] - wyc - slope * w
if (abs (wy) > wx) {
wx = abs (wy)
j = i
peakx = w
}
}
w = Memr[x+j-1]
wy = min (0.99, max (0.01, abs (Memr[y+j-1] - wyc - slope * w) / wx))
sigma = sqrt (-0.5 * (w-peakx)**2 / log (wy))
w = Memr[x+j+1]
wy = min (0.99, max (0.01, abs (Memr[y+j+1] - wyc - slope * w) / wx))
sigma = sigma + sqrt (-0.5 * (w-peakx)**2 / log (wy))
# Do fit.
a[1] = w # initial shift
#a[2] = 0.25 * abs (Memr[x+npts-1] - Memr[x])
a[2] = sigma / 2
call pixind (w0, wpc, log10(w), i)
a[3] = (pixy[i] - (wyc + slope * (w - pixy[left]))) / scale
a[4] = 0.
a[5] = 1.
nlines = 1
iferr {
call dofit ('a', Memr[x], Memr[y], npts, a, nlines, chisq)
call dofit ('b', Memr[x], Memr[y], npts, a, nlines, chisq)
} then {
call erract (EA_WARN)
fit = false
goto done_
}
a[3] = a[3] * scale
wyc = (wyc + slope * wx1) * scale
slope = slope * scale
# Compute model spectrum with continuum and plot.
fit = true
do i = 1, npts {
w = Memr[x+i-1]
Memr[z+i-1] = model (w, a, 5) + wyc + slope * (w - wx1)
}
y2 = rv_maxpix (pixy, ndata)
y1 = rv_minpix (pixy, ndata)
range = abs (y2 - y1)
y2 = y2 + (.15 * range)
y1 = y1 - (.12 * range)
x1 = dex (pixx[1])
x2 = dex (pixx[ndata])
call gswind (gp, x1, x2, y1, y2)
if (where == TOP)
call gsview (gp, 0.115, 0.95, 0.51, 0.865)
else
call gsview (gp, 0.115, 0.95, 0.125, 0.50)
call gseti (gp, G_PLTYPE, GL_DASHED)
call gseti (gp, G_PLCOLOR, RV_LINECOLOR(rv))
call gpline (gp, Memr[x], Memr[z], npts)
call gseti (gp, G_PLTYPE, GL_DOTTED)
call gseti (gp, G_PLCOLOR, C_GREEN)
call gline (gp, wx1, wyc, wx2, wyc + slope * (wx2 - wx1))
call gseti (gp, G_PLTYPE, GL_SOLID)
call gseti (gp, G_PLCOLOR, C_FOREGROUND)
call gflush (gp)
done_
# Log computed values
if (fit) {
w = a[1]
cont = wyc + slope * (w - wx1)
height = a[3]
sigma = a[2]
flux = sigma * height * SQ2PI
shift = (log10(w) - log10(lam)) / wpc
vel = real (rv_shift2vel (rv, shift))
if (cont > 0.)
eqw = -flux / cont
else
eqw = INDEF
call printf (
"center = %8.6g, vel = %8.4g, eqw = %6.4g, fwhm = %6.4g")
call pargr (w)
call pargr (vel)
call pargr (eqw)
call pargr (2.355 * sigma)
}
call sfree (sp)
end
|
