@BeginModule
@NewPage
@Name      = Seaspctl
@Title     = Seasonal percentile values
@Section   = Statistical values
@Class     = Statistic
@Arguments = ifile1 ifile2 ifile3 ofile
@Operators = seaspctl

@BeginDescription
This module computes percentiles over all time steps in @file{ifile1}
of the same season.
The algorithm uses histograms with minimum and maximum bounds given in
@file{ifile2} and @file{ifile3}, respectively. The default number of
histogram bins is 100. The default can be overridden by setting the
environment variable CDO_PCTL_NBINS to a different value. The files
@file{ifile2} and @file{ifile3} must be the result of corresponding
seasmin and seasmax operations, respectively.
The date information for a time step in @file{ofile} is the date of the
last contributing time step in @file{ifile1}. Be careful about the first
and the last output time step, they may be incorrect values if the seasons
have incomplete time steps.
@EndDescription
@EndModule


@BeginOperator_seaspctl
@Title     = Seasonal percentiles
@Parameter = p

@BeginDescription
@IfMan
For every adjacent sequence t_1, ...,t_n of time steps of the same season, it is

o(t,x) = pth percentile {i(t',x), t1 < t' <= tn}
@EndifMan
@IfDoc
For every adjacent sequence \begin{math}t_1, ...,t_n\end{math} of time steps of 
the same season, it is: \\
@BeginMath
o(t,x) = \mbox{\bf pth percentile}\{i(t',x), t_1 < t' \le t_n\}
@EndMath
@EndifDoc
@EndDescription
@EndOperator


@BeginParameter
@Item = p
INTEGER  Percentile number in {1, ..., 99}
@EndParameter


@BeginExample
To compute the seasonal 90th percentile of a time series, use:
@BeginVerbatim
   cdo seasmin ifile minfile
   cdo seasmax ifile maxfile
   cdo seaspctl,90 ifile minfile maxfile ofile
@EndVerbatim
Or shorter using operator piping:
@BeginVerbatim
   cdo seaspctl,90 ifile -seasmin ifile -seasmax ifile ofile
@EndVerbatim
@EndExample
