Next Previous Up Contents
Next: replaceval
Up: Processing Filters
Previous: repeat

#### 6.1.27 `replacecol`

Usage:

       replacecol [-name <name>] [-units <units>] [-ucd <ucd>]
                  [-utype <utype>] [-xtype <xtype>] [-desc <descrip>]
                  <col-id> <expr>

Replaces the content of a column with the value of an algebraic expression. The old values are discarded in favour of the result of evaluating `<expr>`. You can specify the metadata for the new column using the `-name`, `-units`, `-ucd`, `-utype`, `-xtype` and `-desc` flags; for any of these items which you do not specify, they will take the values from the column being replaced.

It is legal to reference the replaced column in the expression, so for example "`replacecol pixsize pixsize*2`" just multiplies the values in column `pixsize` by 2.

Syntax for the `<col-id>` and `<expr>` arguments is described in the manual.

Next Previous Up Contents
Next: replaceval
Up: Processing Filters
Previous: repeat

STILTS - Starlink Tables Infrastructure Library Tool Set
Starlink User Note256
STILTS web page: http://www.starlink.ac.uk/stilts/
Author email: m.b.taylor@bristol.ac.uk
Mailing list: topcat-user@jiscmail.ac.uk