INREGION Tests whether lat/lon points lie within a specified box. BOOL = INREGION(REGION,LAT,LON), where LAT and LON are arrays having the same size, returns an array BOOL which is true (=1) for all LAT/LON pairs which lie inside REGION, and false (=0) otherwise. 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. ______________________________________________________________________ Cell array lat/lon input INREGION also works if LAT and LON are cell arrays. In this case, BOOL is also a cell array, with the Kth element of BOOL, BOOL{K}, being a boolean array of the same size as LAT{K} and LON{K}. ______________________________________________________________________ Multiple boxes INREGION can detect if points are within any of several boxes. To do so, just make REGION a cell array, REGION={R1,R2,...,RN} where the RN are numeric arrays, each with the format [WEST EAST SOUTH NORTH]. In this way one can build up a more general region from the union of several rectangular regions. ______________________________________________________________________ See also REGIONPLOT, INELLIPSE, TRAJEXTRACT. 'inregion --t' runs a test. Usage: bool=inregion(region,lat,lon); _________________________________________________________________ This is part of JLAB --- type 'help jlab' for more information (C) 2006--2016 J.M. Lilly --- type 'help jlab_license' for details