This section describes deprecated commands. For recommended plotting commands, see Section 8.
Some of the parameters for the plotting tasks behave a little bit
differently to other parameters in STILTS, in order to accommodate
related sets of values. If you look at the usage of one of the
plotting commands, for instance in Appendix B.14.1,
you will see that a number of the parameters have the
N" or "
These suffixes can be substituted with any convenient string to identify
parameters which relate to the same input datasets or subsets.
inNparameter must be given to identify the source of the data; any other parameters with the same value of the
Nsuffix relate to that dataset. A dataset here refers to a particular set of plot data from a table; in most cases each input table corresponds to a different dataset, though two datasets may correspond to different sets of columns from the same table.
N. At least the
subsetNSparameter must be given to identify the expression by which the subset is defined; any other parameters with the same value of the
NSsuffix relate to that subset.
Some examples will help to illustrate. The following will generate a Cartesian plot of catalogue position from a single dataset:
stilts plot2d in=gals.fits xdata=RA ydata=DECIn this case the
Nsuffix is present on each of the parameters
ydata, but is equal to the empty string, hence invisible. This is perfectly legal, and convenient when only a single table is in use. If we wish to overplot two datasets however, the dataset suffixes (or one of them at least) have to be made explicit so that different ones can be used, for instance:
stilts plot2d in1=gals.fits xdata1=RA ydata1=DEC in2=stars.fits xdata2=RAJ2000 ydata2=DEJ2000The suffix values "
1" and "
2" are quite arbitrary and can be chosen as convenient, so the following would do exactly the same as the previous example:
stilts plot2d in_GAL=gals.fits xdata_GAL=RA ydata_GAL=DEC in_STAR=stars.fits xdata_STAR=RAJ2000 ydata_STAR=DEJ2000The other parameters which have the
Nsuffix apply only to the matching dataset, so for instance the following:
stilts plot2d in1=gals.fits xdata1=RA ydata1=DEC txtlabel1=NGC_ID in2=stars.fits xdata2=RAJ2000 ydata2=DEJ2000would draw text labels adjacent to the points from only the gals.fits file giving the contents of its NGC_ID column.
NS suffix identifies distinct row subsets
within the same or different datasets. A subset is defined by supplying
a boolean inclusion expression (each row is included only if the
expression evaluates true for that row) as the value of a
If, as in all the examples we have seen so far,
subsetNS parameter is supplied for a given dataset,
then it is treated as a special case, as if a single subset with a name
equal to the empty string (
containing all rows has been specified.
So our earlier simple example:
stilts plot2d in=gals.fits xdata=RA ydata=DECis equivalent to
stilts plot2d in=gals.fits xdata=RA ydata=DEC subset=trueIf we wish to split the plotted points into two sets based on their R-B colours, we can write something like:
stilts plot2d in=gals.fits xdata=RA ydata=DEC subsetX='RMAG-BMAG>0' subsetY='RMAG-BMAG<=0'This will generate a plot with two subsets shown using different colours and/or plotting symbols. These colours and symbols are selected automatically. More control over the appearance can be exercised by setting values for some of the other parameters with
NSsuffixes, for instance
stilts plot2d in=gals.fits xdata=RA ydata=DEC subset_A='RMAG-BMAG>0' colour_A=blue subset_B='RMAG-BMAG<=0' colour_B=redAgain, the suffix strings can be chosen to have any value as convenient.
The dataset- and subset-specific parameters must be put together if there are multiple datasets with multiple subsets to plot simultaneously, for instance:
stilts plot2d in_1=gals.fits xdata_1=RA ydata_1=DEC subset_1_A='RMAG-BMAG>0' colour_1_A=blue subset_1_B='RMAG-BMAG<=0' colour_1_B=red in_2=stars.fits xdata_2=RAJ2000 ydata_2=DEJ2000 colour_2=green
Finally, it's not quite true that the suffixes chosen have no effect
on the plot; they may influence the order in which sets are plotted.
Markers drawn for sets plotted earlier may be obscured by the markers
drawn for sets plotted later, so this can affect the appearance of the plot.
If you want to control this, use the
For instance, to ensure that star data appears on top of galaxy data
in the plot, do the following:
stilts plot2d in_GAL=gals.fits xdata_GAL=RA ydata_GAL=DEC in_STAR=stars.fits xdata_STAR=RAJ2000 ydata_STAR=DEJ2000 sequence=_GAL,_STAR
More examples can be found in the Examples subsections of the individual plotting command descriptions in Appendix B.