TRAJEXTRACT Extracts Lagrangian trajectory segments within given region. [LAT,LON]=TRAJEXTRACT(LAT,LON,REGION) where the input LAT and LON are cell arrays of columns vectors of latitude and longitude, outputs new cell arrays with LAT and LON of the segments contained within REGION. This format for LAT and LON is used by two Lagrangian datasets distributed with JLAB, FLOATS.MAT and DRIFTERS.MAT. Type 'help floats' or 'help drifters' for more details. REGION is an array with the format [WEST EAST SOUTH NORTH]. Longitudes may either be specified on the interval [-180, 180] or on [0, 360]. The region may overlap the prime meridian (LON=0) or the dateline (LON=180). Region boundaries are interpreted to exclude the poles. If an input LAT and LON record contains more than one segment passing through REGION, these are split into separate entries in the output. TRAJEXTRACT with no output arguments overwrites the original named output variables. __________________________________________________________________ Multiple input arguments [LAT,LON,X1,X2,...,XN]=TRAJEXTRACT(LAT,LON,X1,X2,...,XN,REGION) also returns the portions of the cell array variables X1,X2,...,XN within the region. The input XN are the same size as the input LAT and LON. Any of the input XN may also be numerical arrays of the same length as LAT and LON, rather than cell arrays. The corresponding output variable will then also be a numerical array. An example of such a field is the identification number used in FLOATS.MAT and DRIFTERS.MAT. __________________________________________________________________ Specifying length cutoff [LAT,LON,...]=TRAJEXTRACT(LAT,LON,,...,REGION,LMIN) only returns those segments containing LMIN or more points. The default is LMIN=2. __________________________________________________________________ REGION is passed directly to the function INREGION. Thus, REGION can also be a cell array built up from several region boxes. See INREGION for more details on this option. See also INREGION, REGIONPLOT, TRACKEXTRACT. 'trajextract --t' runs a test. 'trajextract --f' generates a sample figure. Usage: [lat,lon]=trajextract(lat,lon,region); [lat,lon,num,id]=trajextract(lat,lon,num,id,region); [lat,lon,num,id]=trajextract(lat,lon,num,id,region,200); trajextract(lat,lon,num,id,region,200); __________________________________________________________________ This is part of JLAB --- type 'help jlab' for more information (C) 2014--2016 J.M. Lilly --- type 'help jlab_license' for details