Plots spectrograms. A spectrogram is a sequence of spectra plotted as vertical 1-d images, each one plotted at a different horizontal coordinate.
This specialised layer is only available for
The way that data values are mapped to colours is usually controlled by options at the level of the plot itself, rather than by per-layer configuration.
layerN=spectrogram tN=<time-expr> ttypeN=DecYear|MJD|JD|Unix|Iso8601 spectrumN=<array-expr> twidthN=<num-expr> inN=<table> ifmtN=<in-format> istreamN=true|false icmdN=<cmds>
All the parameters listed here
affect only the relevant layer,
identified by the suffix
stilts plot2time layer1=spectrogram in1=LRS_NPW_V010_20071101.cdf t1=epoch spectrum1=RX2 auxfunc=linear auxmap=plasma auxclip=0,1 xpix=600 ypix=300 tmin=2007-11-01T00 tmax=2007-11-01T12 ymax=500
icmdN = <cmds>(ProcessingStep)
inN. The value of this parameter is one or more of the filter commands described in Section 6.1. If more than one is given, they must be separated by semicolon characters (";"). This parameter can be repeated multiple times on the same command line to build up a list of processing steps. The sequence of commands given in this way defines the processing pipeline which is performed on the table.
Commands may alteratively be supplied in an external file,
by using the indirection character '@'.
Thus a value of "
causes the file
filename to be read for a list
of filter commands to execute. The commands in the file
may be separated by newline characters and/or semicolons,
and lines which are blank or which start with a
#' character are ignored.
ifmtN = <in-format>(String)
inN. The known formats are listed in Section 5.1.1. This flag can be used if you know what format your table is in. If it has the special value
(auto)(the default), then an attempt will be made to detect the format of the table automatically. This cannot always be done correctly however, in which case the program will exit with an error explaining which formats were attempted. This parameter is ignored for scheme-specified tables.
inN = <table>(StarTable)
-", meaning standard input. In this case the input format must be given explicitly using the
ifmtNparameter. Note that not all formats can be streamed in this way.
<" character at the start, or a "
|" character at the end ("
<syscmd" or "
syscmd|"). This executes the given pipeline and reads from its standard output. This will probably only work on unix-like systems.
istreamN = true|false(Boolean)
inNparameter will be read as a stream. It is necessary to give the
ifmtNparameter in this case. Depending on the required operations and processing mode, this may cause the read to fail (sometimes it is necessary to read the table more than once). It is not normally necessary to set this flag; in most cases the data will be streamed automatically if that is the best thing to do. However it can sometimes result in less resource usage when processing large files in certain formats (such as VOTable). This parameter is ignored for scheme-specified tables.
spectrumN = <array-expr>(String)
The value is an array-valued algebraic expression based on column names as described in Section 10. Some of the functions in the Arrays class may be useful here.
tN = <time-expr>(String)
The value is a Time value algebraic expression based on column names as described in Section 10.
ttypeN = DecYear|MJD|JD|Unix|Iso8601(TimeMapper)
tNis supplied. Options are:
DecYear: Years since 0 AD
MJD: Modified Julian Date
JD: Julian Day
Unix: Seconds since midnight 1 Jan 1970
Iso8601: ISO 8601 string
twidthN = <num-expr>(String)
The value is a numeric algebraic expression based on column names as described in Section 10.