Here are some examples of
stilts tcatn nin=2 in1=obs1.fits in2=obs2.fits out=combined.fits
stilts tcatn nin=3 omode=stats in1=obs1.txt ifmt1=ascii in2=obs2.xml ifmt2=votable in3=obs3.fit ifmt3=fits
stilts tcatn nin=2 in1=survey.vot.gz ifmt2=csv in2=more_data.csv icmd1='addskycoords fk5 galactic RA2000 DEC2000 GLON GLAT' \ icmd1='keepcols "OBJ_ID GLON GLAT"' \ icmd2='keepcols "ident gal_long gal_lat"' \ loccol=FILENAME omode=topcat
ifmt1parameter is required since VOTables can be detected automatically), and the other is a comma-separated-values file (for which the
ifmt2=csvparameter must be given). In the second place, the column structure of the two tables may be quite different. By pre-processing the two tables using the
icmd2parameters, we produce in each case an input table which consists of three columns of compatible types and meanings: an integer identifier and floating point galactic longitude and latitude coordinates. The second table contains such columns to start with, but the first table requires an initial step to convert FK5 J2000.0 coordinates to galactic ones.
tcatnjoins the two doctored tables together, to produce a table which contains only these three columns, with all the rows from both input tables, and sends the result directly to a new or running instance of TOPCAT. An additional column named FILENAME is appended to the table before sending it; this contains "survey.vot.gz" for all the columns from the first table and "more_data.csv" for all the columns from the second one.