@BeginModule
@NewPage
@Name      = Change
@Title     = Change field header
@Section   = Modification
@Class     = Modification
@Arguments = ifile ofile
@Operators = chcode chvar chlevel chlevelc chlevelv

@BeginDescription
This module reads fields from @file{ifile}, changes some header values
and writes the results to @file{ofile}. The kind of changes depends on 
the actual operator.
@EndDescription
@EndModule


@BeginOperator_chcode
@Title     = Change code number
@Parameter = oldcode newcode [...]

@BeginDescription
Changes some user given code numbers to new user given values.
@EndDescription
@EndOperator


@BeginOperator_chvar
@Title     = Change variable name
@Parameter = ovar nvar ...

@BeginDescription
Changes some user given variable names to new user given names.
@EndDescription
@EndOperator


@BeginOperator_chlevel
@Title     = Change level
@Parameter = oldlev newlev ...

@BeginDescription
Changes some user given levels to new user given values.
@EndDescription
@EndOperator


@BeginOperator_chlevelc
@Title     = Change level of one code
@Parameter = code oldlev newlev

@BeginDescription
Changes one level of a user given code number.
@EndDescription
@EndOperator


@BeginOperator_chlevelv
@Title     = Change level of one variable
@Parameter = var oldlev newlev

@BeginDescription
Changes one level of a user given variable.
@EndDescription
@EndOperator


@BeginParameter
@Item = code
INTEGER  Code number
@Item = oldcode,newcode,...
INTEGER  Pairs of old and new code numbers
@Item = var
STRING   Variable name
@Item = ovar,nvar,...
STRING   Pairs of old and new variable names
@Item = oldlev
FLOAT    Old level
@Item = newlev
FLOAT    New level
@Item = oldlev,newlev,...
FLOAT    Pairs of old and new levels
@EndParameter


@BeginExample
To change the code number 98 to 179 and 99 to 211 use:
@BeginVerbatim
   cdo chcode,98,179,99,211 ifile ofile
@EndVerbatim
@EndExample
