@BeginModule
@NewPage
@Name      = Intyear
@Title     = Year interpolation
@Section   = Interpolation
@Class     = Interpolation
@Arguments = ifile1 ifile2 obase
@Operators = intyear
@EndModule


@BeginOperator_intyear
@Title     = Interpolation between two years
@Parameter = years


@BeginDescription
This operator performs linear interpolation between two years, timestep by timestep.
The input files need to have the same structure with the same variables.
The output files will be named @file{<obase><yyyy><suffix>} where @file{yyyy} will be the year and 
@file{suffix} is the filename extension derived from the file format.
@EndDescription


@BeginParameter years
@Item = years
INTEGER  Comma separated list of years
@EndParameter
@EndOperator


@BeginEnvironment
@Item = CDO_FILE_SUFFIX
Set the default file suffix. This suffix will be added to the output file 
names instead of the filename extension derived from the file format. 
Set this variable to NULL to disable the adding of a file suffix.
@EndEnvironment


@BeginExample
Assume there are two monthly mean datasets over a year. The first dataset 
has 12 timesteps for the year 1985 and the second one for the year 1990.
To interpolate the years between 1985 and 1990 month by month use:
@BeginVerbatim
   cdo intyear,1986,1987,1988,1989 ifile1 ifile2 year
@EndVerbatim
Example result of '{\tt dir year*}' for netCDF datasets:
@BeginListing
   year1986.nc year1987.nc year1988.nc year1989.nc
@EndListing
@EndExample
