As an example of use of the table file system, we here describe the tutorial procedure executed via the TUTORIAL/TABLE command. This procedure uses a subset of the Uppsala General Catalogue. The format of the catalogue is defined in the file ugc.fmt as follows:
DEFINE/FIELD 9 20 R G11.6 :RA "HOUR" DEFINE/FIELD 21 32 R G11.6 :DEC "DEGREE" DEFINE/FIELD 33 44 R G11.6 :DB "ARC.MIN." DEFINE/FIELD 45 56 R G11.6 :DR "ARC.MIN." DEFINE/FIELD 57 68 R G11.6 :BT "MAGNITUDE" DEFINE/FIELD 69 80 R G11.6 :RV "KM.SEC-1" END
This file and the actual ASCII data in ugc.dat will be copied into your workspace. The first four lines of the data file have the following layout:
12345678901234567890123456789012345678901234567890123456789012345678901234567890 0.0117 15.87 6.500 6.300 12.00 1047. 0.0233 20.47 4.000 3.800 12.70 * 0.2933 59.03 8.000 10.00 * * 0.3583 16.20 5.800 5.100 14.60 *(The ruler, of course, is not part of the data file.)
This tutorial shows the usage of some of the basic table file commands to analyse and display the data set.
CREATE/TABLE ugc 10 700 ugc ! create the table file (UGC.tbl) NAME/COL ugc :RA F11.3 ! change format NAME/COL ugc :DEC G12.6 ! change format SHOW/TABLE ugc ! display structure READ/TABLE ugc @1 @30 ! display a few entries ! PLOT/TABLE ugc :DR :DB ! plot diameters in red and blue bands ! REGR/LINEAR ugc :DB :DR ! linear regression on these variables READ/KEY OUTPUTD ! and display stored coefficients ! READ/HIST ugc :BT ! display results on terminal PLOT/HIST ugc :BT ! and plot device ! SELECT/TAB ugc :BT.LT.13.5 ! select brightest objects ! STAT/TAB ugc :DR ! do statistics on the subset, READ/HIST ugc :DR ! display the result ! PLOT/TAB ugc :BT :RV ! and plot the selected set ! SELECT/TAB ugc :RV.GT.4000.0 ! select new subset with largest rad.vel. ! PRINT/TAB ugc ! print them ! COMPUTE/TAB ugc :MBT = :BT-25.-5.*LOG10(:RV/50) ! compute abs.magnitude NAME/COL ugc :MBT "ABS.B.MAG." ! include units ! COMPUTE/TAB ugc :SIZE = :RV*SIN(0.000291*:DB)*20 ! diameter NAME/COL ugc :SIZE "KPC" ! include units ! PLOT/TAB ugc :MBT :SIZE ! display result
=31 =3 =1999