@BeginModule
@NewPage
@Name      = EcaPd
@Title     = Precipitation days index per time period
@Section   = Climate indices
@Class     = Climate index
@Arguments = ifile ofile
@Operators = eca_pd eca_r10mm eca_r20mm

@BeginDescription
Let @file{ifile} be a time series of the daily precipitation amount RR in [mm] (or alternatively in [kg m-2]),
then the number of days where RR is at least @math{x} mm is counted. 
eca_r10mm and eca_r20mm are specific ECA operators with a daily precipitation amount of 10 and 20 mm respectively.
The date information of a timestep in ofile is the date of the last contributing timestep in @file{ifile}.
@EndDescription
@EndModule


@BeginOperator_eca_pd
@Title     = Precipitation days index per time period
@Parameter = x

@BeginDescription
Generic ECA operator with daily precipitation sum exceeding @math{x} mm.
@EndDescription
@EndOperator

@BeginOperator_eca_r10mm
@Title     = Heavy precipitation days index per time period

@BeginDescription
Specific ECA operator with daily precipitation sum exceeding 10 mm.
@EndDescription
@EndOperator

@BeginOperator_eca_r20mm
@Title     = Very heavy precipitation days index per time period

@BeginDescription
Specific ECA operator with daily precipitation sum exceeding 20 mm.
@EndDescription
@EndOperator


@BeginParameter x
@Item = x
FLOAT   Daily precipitation amount threshold in [mm]
@EndParameter


@BeginNote
Precipitation rates in [mm/s] have to be converted to precipitation amounts (multiply with 86400 s).
Apart from metadata information the result of eca_pd,1 and eca_rr1 is the same.
@EndNote


@BeginExample
To get the number of days with precipitation greater than 25 mm for a time series of daily precipitation amounts use:
@BeginVerbatim
   cdo eca_pd,25 ifile ofile
@EndVerbatim
@EndExample
