@BeginModule
@Name      = EcaCfd
@Title     = Consecutive frost days index per time period
@Section   = Climate indices
@Class     = Climate index
@Arguments = ifile ofile
@Operators = eca_cfd

@BeginDescription
Let @file{ifile} be a time series of daily minimum temperatures TN,
then counted is the largest number of consecutive days where
TN < 0 @celsius. Note that TN have to be given in units of Kelvin.
The date information of a time step in @file{ofile} is the date of
the last contributing time step in @file{ifile}.
@EndDescription
@EndModule


@BeginOperator_eca_cfd
@Title     = Consecutive frost days index per time period
@EndOperator


@BeginExample
To get the largest number of consecutive frost days of a time
series of daily minimum temperatures use:
@BeginVerbatim
   cdo eca_cfd tnfile ofile
@EndVerbatim
@EndExample
