1
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2
%.COPYRIGHT (c) 1990 European Southern Observatory
5
%.KEYWORDS MIDAS, help files, CENTER/GAUSS
6
%.PURPOSE On-line help file for the command: CENTER/GAUSS
7
%.VERSION 1.0 07-FEB-1990 : Creation, KB
8
%.VERSION 1.1 02-MAR-1992 : Update, KB
9
%.VERSION 1.2 09-NOV-1992 : Update, KB
10
%----------------------------------------------------------------
14
CENTER/GAUSS 29-JUN-2011 KB
16
CENTER/GAUSS [in_specs] [out_specs] [out_opt] [curs_specs]
17
[wsize] [zw_option] [invert_flag]
18
find intensity weighted center
21
Compute the central position of the specified object by fitting
22
a Gaussian to the marginal distributions in both the x- and
23
y-directions (or just in x).
26
Position, fitting, centering.
29
CENTER/GAUSS [in_specs] [out_specs] [out_opt] [curs_specs]
30
[wsize] [zw_option] [invert_flag]
32
in_specs = input specifications, either
33
(a) CURSOR - if the subimages are interactively chosen via the
35
(b) GCURSOR[,color] - if the subimages are interactively
36
chosen via the graphic cursor,
37
if color is given, the fitted Gaussian is plotted
38
in that color to distinguish it better from the
39
plotted image - color = 1,...,8 or blue, red, ... ,or
42
(c) image,table - if the subimages are defined in a table in the
43
columns labeled :XSTART, :XEND, :YSTART and :YEND, or
44
only columns :XSTART and :XEND (1-dim centering) or only
45
single column :X_POSITION (two rows per interval needed);
46
(d) image - if subimage will be a (max) 200 * 200 window around
48
(e) image,xfrpix,yfrpix - if subimage will be a window of
49
param. `wsize' around xfrpix,yfrpix (frame pixels)
52
out_specs = output specifications:
53
(x) table name, may be same as given in in_specs
54
(y) if same table, only the xcenter, ycenter, xerr, yerr,
55
xsigma, ysigma, xfwhm, yfwhm, icent and status will be
57
:XCEN, :YCEN, :XERR, :YERR, :XSIG,
58
:YSIG, :XFWHM :YFWHM :ICENT :STATUS
59
if new table, then in addition to the columns explained
60
above, also the columns labeled :XSTART, :YSTART, :XEND,
61
:YEND and :NO will be filled
62
(z) descriptor,D if the results should be stored in a real
63
descriptor of the involved image frame;
64
data will be stored as xstart, ystart, xend, yend, xcenter,
65
ycenter, xerr, yerr, xsigma, ysigma, return_status,
66
xfwhm, yfwhm and icent
67
Per Default the values are displayed only on the terminal and
68
stored in the keyword OUTPUTR which is filled as follows:
69
xstart, ystart, xend, yend, xcenter, ycenter, xerr, yerr,
70
xsigma, ysigma, return_status, xfwhm, yfwhm, icent
71
Xstart, ystart, xend, yend, xcenter, ycenter are also stored
72
as double precision values in keyword OUTPUTD(1 - 6).
74
out_opt = A, append data to a table (or descriptor), else start at
75
the beginning, only applicable to (x) or (z)
76
ID, write also column labeled :IDENT to output table,
77
only applicable to (x)
78
EMISSION, assumes emission lines, applicable to (b)
79
ABSORPTION, assumes absorption lines, applicable to (b)
81
curs_specs = no_curs,drawflag,max_input:
82
no_curs = 1 or 2, if single cursor a fixed subimage according
83
to next parameter `wsize' is used; for 2 cursors the size of
84
subimage is determined by the size of the cursor rectangle.
85
drawflag = option for drawing subwindow limits in the overlay
87
max_input = max. of cursor inputs.
88
This parameter is only used if in_specs = CURSOR (a);
91
wsize = no. of x-and y-pixels for subwindow centered via the
92
single cursor or `inp_specs' (e);
95
zw_option = zwindow_flag,zoom;
96
zwindow_flag = W for zoom window, N for none,
97
zoom = initial zoom factor;
98
only applicable to X11 window displays and option (a),
99
defaulted to N,4 (see the help of GET/CURSOR for more info about
100
the additional functionality provided in that mode);
102
invert_flag = YES or NO;
103
if the objects are at a minimum and not maximum of the data,
104
i.e. instead of a Gaussian `peak' you have a Gaussian `valley',
105
set this par. to YES.
109
CENTER/MOMENT, CENTER/IQE, MAGNITUDE/CENTER
112
When using the cursor input option, a cursor window will appear
114
For X-Windows use the mouse to move the complete window (or single
115
cursor), use the arrow keys to change window size. Left mouse
116
button (or RETURN key) is ENTER button, right button is
118
If you also use the `zw_option', the cursor in the main display
119
is only used to define the subwindow to work on. Then move the
120
cursor to the auxiliary (zoom) window and proceed as described
122
When using the graphic cursor option (b), the command needs
123
two cursor positions defining the 1D interval to be used. Any key
124
can be used to input the cursor. Use SPACE-BAR to exit.
125
Also be aware the fitted will be done on the LAST plotted data.
126
I.e. when addtional data is plotted using an overplot command
127
the CENTER command will work on this overplotted data set.
128
When using the out_opt ID for table output, computations proceed
129
after pressing the ENTER button and(!) entering also an identifier
130
of max. 8 characters and hitting RETURN on the keyboard.
131
Otherwise the string IDabcd will be written into column :IDENT
132
with "abcd" the sequence number.
133
The return status from the centering algorithm is specified as
135
< 0 = estimation failed
137
1 = ambiguous sources
141
If you also need the angle of the 2-dim Gaussian (if it's not
142
perfectly round) of the major axis with the X-axis, use the
143
command CENTER/IQE (ImageQualityEstimate).
148
Use cursor to define subimages and display start- and
149
end-coordinates of subimage as well as center values and
150
associated errors and return status on terminal only
152
2) CENTER/GAUSS CURSOR values,d
153
as 1) but write data to beginning of real descriptor VALUES
156
3) CENTER/GAUSS cursor VALUES,D A
157
as 2) but append data to the end of real descriptor VALUES
159
4) CENTER/GAUSS CURSOR values
160
as 1) but store data into table values.tbl (will be created
163
6) CENTER/GAUSS ccd001,sources
164
use columns :XSTART, :YSTART, :XEND and :YEND of `sources.tbl'
165
to define the subimages of image ccd001.bdf;
168
7) CENTER/GAUSS ccd001,sources VALUES,D
169
as 6) but write results into real descr values of frame
172
8) CENTER/GAUSS ccd001,sources sources
173
as 6) but store results also in input table sources.tbl
175
9) CENTER/GAUSS ccd001,sources center
176
as 8) but store results into new table `center.tbl'
178
10) CENTER/GAUSS ccd001,233,402 ? ? ? 20,20
179
use a subwindow of 20x20 pixels centered at frame
180
pixels 233,402 of `ccd001.bdf'
182
11) CENTER/GAUSS cursor p6=w
183
as 1) but use zoom window to determine working area via cursor,
184
but we need X11 for that...
186
12) CENTER/GAUSS GCURSOR table EMISSION
187
generate table `table.tbl' with positions of emission lines
188
defined with the graphic cursor.
190
13) CENTER/GAUSS GCURSOR,red
191
find center of cursor defined subimage, plot fitted gaussian
192
in blue instead of given plot color