@BeginModule
@NewPage
@Name      = Merstat
@Title     = Meridional statistical values
@Section   = Statistical values
@Class     = Statistic
@Arguments = ifile ofile
@Operators = mermin mermax mersum mermean meravg merstd merstd1 mervar mervar1 merpctl

@BeginDescription
This module computes meridional statistical values of the input fields.
According to the chosen operator the meridional minimum, maximum, sum, average,
variance, standard deviation or a certain percentile is written to @file{ofile}.
This operator requires all variables on the same regular lon/lat grid.
@EndDescription
@EndModule


@BeginOperator_mermin
@Title     = Meridional minimum

@BeginDescription
For every longitude the minimum over all latitudes is computed.
@EndDescription
@EndOperator


@BeginOperator_mermax
@Title     = Meridional maximum

@BeginDescription
For every longitude the maximum over all latitudes is computed.
@EndDescription
@EndOperator


@BeginOperator_mersum
@Title     = Meridional sum

@BeginDescription
For every longitude the sum over all latitudes is computed.
@EndDescription
@EndOperator


@BeginOperator_mermean
@Title     = Meridional mean

@BeginDescription
For every longitude the area weighted mean over all latitudes is computed.
@EndDescription
@EndOperator


@BeginOperator_meravg
@Title     = Meridional average

@BeginDescription
For every longitude the area weighted average over all latitudes is computed.
@EndDescription
@EndOperator


@BeginOperator_mervar
@Title     = Meridional variance

@BeginDescription
For every longitude the variance over all latitudes is computed. Divisor is n.
@EndDescription
@EndOperator


@BeginOperator_mervar1
@Title     = Meridional variance

@BeginDescription
For every longitude the variance over all latitudes is computed. Divisor is (n-1).
@EndDescription
@EndOperator


@BeginOperator_merstd
@Title     = Meridional standard deviation

@BeginDescription
For every longitude the standard deviation over all latitudes is computed. Divisor is n.
@EndDescription
@EndOperator


@BeginOperator_merstd1
@Title     = Meridional standard deviation

@BeginDescription
For every longitude the standard deviation over all latitudes is computed. Divisor is (n-1).
@EndDescription
@EndOperator


@BeginOperator_merpctl
@Title     = Meridional percentiles
@Parameter = p

@BeginDescription
For every longitude the pth percentile over all latitudes is computed.
@EndDescription
@EndOperator


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


@BeginExample
To compute the meridional mean of all input fields use:
@BeginVerbatim
   cdo mermean ifile ofile
@EndVerbatim

To compute the 50th meridional percentile (median) of all input fields use:
@BeginVerbatim
   cdo merpctl,50 ifile ofile
@EndVerbatim
@EndExample
