source: tags/Release-2/bugs/asap0000.txt

Last change on this file was 570, checked in by mar637, 19 years ago

asap0000 merge from Release-1 branch
  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 4.4 KB
Line 
1asap0000
2========
3Hi
4
5Jim Lovell has discovered a strange corruption bug in asap.
6
7When we run:
8
9 scans = scantable('2005-03-09_172811_t002.rpf')
10 scans.summary(verbose=True)
11
12repeatably the source position become corrupted (generally it seems to be
13after the third "scantable" construction.
14
15The above data is in /DATA/VULCAN_1/cphillip/vulcan/data/asap, but I think
16any data will do.
17
18Cheers
19Chris
20
21
22---------------------------------------------------------
23**OK
24
25ASAP> scans.summary(verbose=True)
26
27--------------------------------------------------------------------------------
28 Scan Table Summary
29--------------------------------------------------------------------------------
30Beams:         1
31IFs:           2
32Polarisations: 1
33Channels:      4096
34
35Observer:      Auto_Spec
36Obs Date:      2005/03/09/17:29:22
37Project:       NGC6334Fw
38Obs. Type:
39Antenna Name:  DSS-43
40Flux Unit:     K
41Rest Freqs:    [2.39639e+10] [Hz]
42Abcissa:       Channel
43Cursor:        Beam[0] IF[0] Pol[0]
44
45Scan Source         Position (J2000)        Time      Integration
46FreqIDs
47--------------------------------------------------------------------------------
48  0  NGC6334Fw      17:18:23.4 -35.47.01.3  17:30:37    1 x    02:31.0
49[0, 1] [0]
50  1  NGC6334F       17:20:53.4 -35.47.01.3  17:33:43    1 x    02:33.9
51[0, 1] [0]
52  2  NGC6334F       17:20:53.4 -35.47.01.3  17:36:34    1 x    02:33.9
53[2, 3] [0]
54  3  NGC6334Fe      17:23:23.4 -35.47.01.3  17:39:40    1 x    02:33.9
55[2, 3] [0]
56  4  NGC6334Fw      17:18:23.4 -35.47.01.3  17:42:11    1 x    01:22.9
57[4, 5] [0]
58
59Table contains 5 integration(s) in 5 scan(s).
60
61
62FreqID  Frame   RefFreq(Hz)     RefPix   Increment(Hz)
63--------------------------------------------------------------------------------
640       TOPO    2.396822e+10    2048      3906.25
651       TOPO    2.4143763e+10   2048      3906.25
662       TOPO    2.3968219e+10   2048      3906.25
673       TOPO    2.4143763e+10   2048      3906.25
684       TOPO    2.3968219e+10   2048      3906.25
695       TOPO    2.4143762e+10   2048      3906.25
70--------------------------------------------------------------------------------
71
72
73**BAD
74
75ASAP> scans = scantable('2005-03-09_172811_t002.rpf')
76Importing data...
77Auto averaging integrations...
78Weighting type selected : None
79
80ASAP> scans.summary(verbose=True)
81
82--------------------------------------------------------------------------------
83 Scan Table Summary
84--------------------------------------------------------------------------------
85Beams:         1
86IFs:           2
87Polarisations: 1
88Channels:      4096
89
90Observer:      Auto_Spec
91Obs Date:      2005/03/09/17:29:22
92Project:       NGC6334Fw
93Obs. Type:
94Antenna Name:  DSS-43
95Flux Unit:     K
96Rest Freqs:    [2.39639e+10] [Hz]
97Abcissa:       Channel
98Cursor:        Beam[0] IF[0] Pol[0]
99
100Scan Source         Position (J2000)        Time      Integration
101FreqIDs
102--------------------------------------------------------------------------------
103  0  NGC6334Fw      17:47:49.9 +16.00.27.6  17:30:37    1 x    02:31.0
104[0, 1] [0]
105  1  NGC6334F       17:03:08.2 -44.33.03.4  17:33:43    1 x    02:33.9
106[0, 1] [0]
107  2  NGC6334F       03:46:52.4 +56.43.05.6  17:36:34    1 x    02:33.9
108[2, 3] [0]
109  3  NGC6334Fe      17:47:49.9 +16.00.27.6  17:39:40    1 x    02:33.9
110[2, 3] [0]
111  4  NGC6334Fw      17:03:08.2 -44.33.03.4  17:42:11    1 x    01:22.9
112[4, 5] [0]
113
114Table contains 5 integration(s) in 5 scan(s).
115
116
117FreqID  Frame   RefFreq(Hz)     RefPix   Increment(Hz)
118--------------------------------------------------------------------------------
1190       TOPO    2.396822e+10    2048      3906.25
1201       TOPO    2.4143763e+10   2048      3906.25
1212       TOPO    2.3968219e+10   2048      3906.25
1223       TOPO    2.4143763e+10   2048      3906.25
1234       TOPO    2.3968219e+10   2048      3906.25
1245       TOPO    2.4143762e+10   2048      3906.25
125--------------------------------------------------------------------------------
126
127
128Seems to be a good old rpfits (fortran) memory problem.
129
130repeatedly opening an rpfits file with the read buggers up the refbeam field.
131as the summary function looks at the refbeam to determine the positions it
132fails as the reader returns a "random" value.
133
134I have a chat to Mark.
135
136Malte.
137
138Mark,
139
140The attached data has only one beam.
141This only occurs on this data set.
142If I convert it to sdfits the problem is solved as you don't write this column
143out unless it is MX data.
144For now I have put a kludge in, which checks nBeam >1 and only then gets the
145refbeam from the data.
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