Example

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         *

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