@BeginModule
@NewPage
@Name      = Daystat
@Title     = Daily statistical values
@Section   = Statistical values
@Class     = Statistic
@Arguments = ifile ofile
@Operators = daymin daymax daysum daymean dayavg daystd

@BeginDescription
This module computes statistical values over time steps of the same day.
Depending on the actual operator the minimum, maximum, sum, average
or standard deviation of time steps of the same day is written to @file{ofile}.
The date information for a time step in @file{ofile} is the date of the last 
contributing time step in @file{ifile}.
@EndDescription
@EndModule


@BeginOperator_daymin
@Title     = Daily minimum

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

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


@BeginOperator_daymax
@Title     = Daily maximum

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

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


@BeginOperator_daysum
@Title     = Daily sum

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

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


@BeginOperator_daymean
@Title     = Daily mean

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

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


@BeginOperator_dayavg
@Title     = Daily average

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

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


@BeginOperator_daystd
@Title     = Daily standard deviation

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

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


@BeginExample
To compute the daily mean of a time series, use:
@BeginVerbatim
   cdo daymean ifile ofile
@EndVerbatim
@EndExample
