./guide
scan_info.pro
- Last modification date:
- Sun Oct 22 03:20:02 2017
Get scan information structure from the appropriate I/O object.
This uses !g.line to determine which I/O object to get the
information from, unless keep is set, in which case it gets it from
the keep file.
Note that this may return more than one structure (an array of
structures would be returned). This can happen if the same scan
number appears in the data with more than one timestamp. The
instance and timestamp keywords of the various data retrieval
procedures (getscan, get, getnod, getps, etc) can be used to
differentiate between these duplicate scans. The instance keyword
in those cases corresponds to the element number of the array
returned by scan_info. The timestamp keyword corresponds to the
timestamp field in the scan_info structure.
The data corresponding to a given instance are always found in
consecutive records. The index_start and nrecords fields can be
used to get just the data associated with a specific instance. See
the examples.
The fields in the returned structure are:
- SCAN, the scan number, long integer
- PROCSEQN, the procedure sequence number, long integer
- PROCEDURE, the procedure name, string
- TIMESTAMP, the timestamp associated with this scan, string
- FILE, the name of the file where this scan was found
- N_INTEGRATION, the number of integrations, long integer. Note
that different samplers may have different numbers of integrations.
This value is the number of unique times (MJD) found for this scan.
Use N_SAMPINTS for the number of integrations from a given sampler.
- N_FEEDS, the number of feeds, long integer
- FDNUMS, the specific FDNUM values for this scan.
- N_IFS, the number of IFs, long integer
- IFNUMS, the specific IFNUM values for this scan.
- IFTABLE, a 3-axis array indicating which combinations of ifnum,
fdnum and plnum are present in the data. The first axis is ifnum,
the second axis is fdnum and the 3rd is plnum. Combinations with
data have 1 in this array. Combinations without data have a 0.
Note: IDL removes any trailing axis of length 1 (degenerate) so care
must be taken when using the shape of this array. E.g. if there is
no third axis, then there is only one plnum, plnum=0.
- N_SWITCHING_STATES, the number of switching states, long integer
- N_CAL_STATES, the number of cal switching states, long integer
- N_SIG_STATES, the number of sig switching states, long integer
- N_WCALPOS, the total number of unique WCALPOS values in this
scan. (spectral line data only)
- WCALPOS, a vector giving the list of unique WCALPOS
(WBand receiver calposition) values for this scan. (spectral line
data only)
- N_POLARIZATIONS, the number of unique polarizations, long
integer, will always be less then or equal to 4.
- POLARIZATIONS, a vector containing the actual
polarizations, string (unused elements are the null string).
- PLNUMS, vector containing the PLNUM values
corresponding to each POLARIZATION, long integer (unused elements
are -1)
- FEEDS, a vector containing the unique feed ids, long
integer (unused elements are -1)
- BANDWIDTH, a vector containing the unique bandwidths, one for each IF
(Hz)
- INDEX_START, the starting index number for this scan.
- NRECORDS, the total number of records in this scan.
- N_SAMPLERS, the total number of unique sampler names in this scan.
- SAMPLERS, the list of unique sampler names.
- N_SAMPINTS, the number of integrations for each sampler.
- N_CHANNELS, the number of channels in each spectrum for each sampler.
- Returns
-
Scan information structure. Returns -1 on error.
- Examples
-
Get all of the data associated with one scan.
a = scan_info(65)
indx = lindgen(a.nrecords) + a.index_start
d65 = getchunk(index=indx)
... do stuff with d65, but don't forget to free it when done
data_free, d65
Find paired scan's and their info structure (e.g. position switched)
a = scan_info(65)
b = find_paired_info(a)
- Version
-
$Id$
| Parameters |
scan
in, required
integer
|
Scan number to get
information on.
|
file
in, optional
string
|
Limit the search for
matching scans to a specific file. If omitted, scans are found in
all files currently opened through filein (a single file) or dirin
(possibly multiple files).
|
| Keywords |
keep
in, optional
boolean
|
If set, the scan
information comes from the keep file.
|
quiet
in, optional
boolean
|
When set, suppress most
error messages. Useful when being used within another procedure.
|
count
in, optional
integer
|
Returns the number of
elements of the returned array of scan_info structures.
|
Produced by IDLdoc 1.6 on Sun Oct 22 03:20:10 2017