Monpctl

@BeginModule
@Name      = Monpctl
@Title     = Monthly percentile values
@Section   = Statistical values
@Class     = Statistic
@Arguments = infile1 infile2 infile3 outfile
@Operators = monpctl

@BeginDescription
This operator computes percentiles over all timesteps of the same month in @file{infile1}.
The algorithm uses histograms with minimum and maximum bounds given in @file{infile2} and
@file{infile3}, respectively. The default number of histogram bins is 101.
The default can be overridden by defining the environment variable @env{CDO_PCTL_NBINS}.
The files @file{infile2} and @file{infile3} should be the result of corresponding @mod{monmin}
and @mod{monmax} operations, respectively.
The time of @file{outfile} is determined by the time in the middle of all contributing timesteps of @file{infile1}.
@EndDescription
@EndModule


@BeginOperator_monpctl
@Title     = Monthly percentiles
@Parameter = p

@BeginDescription
@IfMan
For every adjacent sequence t_1, ...,t_n of timesteps of the same month it is:

o(t,x) = pth percentile {i(t',x), t_1<t'<=t_n}
@EndifMan
@IfDoc
\vspace*{1mm}
For every adjacent sequence \begin{math}t_1, ...,t_n\end{math} of timesteps of the same month it is: \\
\vspace*{1mm}

@BeginMath
o(t,x) = \mbox{\textbf{pth percentile}} \{i(t',x), t_1 < t' \leq t_n\}
@EndMath
@EndifDoc
@EndDescription
@EndOperator


@BeginParameter
@Item = p
FLOAT  Percentile number in {0, ..., 100}
@EndParameter


@BeginEnvironment
@Item = CDO_PCTL_NBINS
Sets the number of histogram bins. The default number is 101.
@EndEnvironment


@BeginExample
To compute the monthly 90th percentile of a time series use:
@BeginVerbatim
   cdo monmin infile minfile
   cdo monmax infile maxfile
   cdo monpctl,90 infile minfile maxfile outfile
@EndVerbatim
Or shorter using operator piping:
@BeginVerbatim
   cdo monpctl,90 infile -monmin infile -monmax infile outfile
@EndVerbatim
@EndExample