Subversion Repositories lagranto.ecmwf

.TH extract
.SH extract
.B extract - extract columns, times, single trajectories and starting positions 
.SH SYNOPSIS
.B extract 
.I inptra
.I outtra
.I mode
.SH DESCRIPTION
Extract columns, times, single trajectories or starting positions from an input trajectory file 
.I inptra
and write output to a new trajectory file
.I outtra. 
The different extraction modes are specified with 
.I mode.
Note: the time, longitude, latitude and pressure need not be extracted beacuse they are an integral part of every trajectory file - they are extracted by default.
.SH EXTRACTION MODE 
.TP 5
.B -var
extract columns of a trajectory file; the columns can be listed by name (e.g. -var TH PV RH) or a range of columns can be specified by the "to" operator (e.g. -var TH to PV). The two modes can also be combined: "-var TH to PV RH" extracts all columns between TH and PV, and additionally RH.
.TP 5
.B -time 
extract trajectory times; the times can be given as a list of times (e.g. -time 6 12) or as a time range (e.g. -time 6 to 18). 
.TP 5
.B -tra
extract single trajectories; the index of the trajectories can be specified as a list (e.g. -tra 10 12 14) or as a range of trajectories (e.g. -tra 10 to 20).
.TP 5
.B -startf
extract list (longitude, latitude, pressure) of starting positions ofvthe trajectory file (corresponding to time 0).
.TP 5
.B -index
extract single trajectories - the trajectory indices (from 1 to #trajectories) are given on a file (e.g. -index filename).
.TP 5
.B -boolean
extract single trajectories - the trajectory are specified on a boolean (0/1) file (e.g. -boolean filename).
.TP 5
.B -pattern
extract all trajectories which match the pattern given; the pattern is a list of numbers. It is then checked whether
these numbers occur in a trajectory (all at one time).
.SH EXAMPLES
.TP 5
.B [1] extract inptra outtra -time 6 to 36 72
read input trajectory file "inptra", extract times 6 to 36 and additionally time 72, and write output to trajectory file "outtra".
.TP 5
.B [2] extract inptra outtra -index indfile
reads input trajectories from "inptra" and write all trajectories to "outtra" which are listed in the file "indfile". In "infile" the indices of selected trajectories are listed line-by-line.
.TP 5
.B [3] extract inptra outtra -pattern -999.99 
extracts all trajectories which have a missing data (-999.99) entry.
.TP 5
.B [4] extract inptra outtra -pattern 0.00   -44.25  -28.47   140
extracts all trajectories which have the numbers '0.00   -44.25  -28.47   140' in their list. This options
is convenient to search for specific times and positions, and then to see the complete trajectory.
.SH AUTHOR
Written by Michael Sprenger and Heini Wernli (January 2011)