AIPS HELP file for TASRT in 31DEC21
As of Wed May 5 15:44:41 2021
TASRT: Task to sort extension tables.
INNAME Main input file (name).
INCLASS Main input file (class).
INSEQ 0.0 9999.0 Main input file (seq. #).
0 => high
INDISK Disk unit #. 0 => any
INEXT Table type (e.g. 'CC')
INVERS Input table file version no.
OUTVERS Output table file version.
CPARM Keys & weights.
1,2=> col. & wt pri. key 1.
3,4=> col. & wt sec. key 1.
5,6=> col. & wt pri. key 2.
7,8=> col. & wt sec. key 2.
BADDISK Disks to avoid for scratch
Use: TASRT sorts the contents of a given AIPS extension table
producing a new table. A two key sort is supported and
each key may be a linear combination of one or two
columns. Sorts may be done on character, logical, or
bit columns, but only one column may be used for each
sort key in that case.
INNAME......Main file name (name). Standard defaults.
INCLASS.....Main file name (class). Standard defaults.
INSEQ.......Main file name (seq. #). 0 => highest.
INDISK......Disk drive # of image. 0 => any.
INEXT.......Extension file type ' ' => 'TA'
INVERS......Input extension file version # 0 => highest.
OUTVERS.....Input extension file version # 0 => highest.
CPARM.......Table columns and factors for sorting.
The columns and factors are specified in CPARM,
the first (most slowly varying key) is:
KEY_VALUE1 = COL_VALUE(CPARM(1)) * CPARM(2) +
COL_VALUE(CPARM(3)) * CPARM(4)
The faster changing key value is:
KEY_VALUE2 = COL_VALUE(CPARM(5)) * CPARM(6) +
COL_VALUE(CPARM(7)) * CPARM(8)
In the case of bit or character strings only one
column is used to generate the key values. In
this case, CPARM(2) is the first character and
CPARM(4) is the number of characters to use for
the first key; CPARM(6) is the first character
and CPARM(8) is the number of characters to use
for the second key.
Sorting is normally in ascending order of the
keys, for decending order use a negative factor
for the relevant key. Factors of 0 => 1.0. To
sort using the ABSOLUTE value of the column, set
the column number to negative.
For a single key sort use CPARM(5)=0. To use
a single column as the sort key set CPARM(3)=0
and/or CPARM(7)=0 as appropriate.
Example: sort by col. 1 (slowest varying) and
col. 6 (fastest) in decending order:
To sort by ascending absolute value col. 2 and,
secondarily, by descending value of col. 1:
CPARM = -2, 1.0, 0, 0, 1, -1., 0, 0
BADDISK.....Disk drive numbers to avoid for scratch files.