Filter latitudes and longitudes based on underlying data grid
[latout,lonout] = filterm(lat,lon,Z,R,allowed)
[latout,lonout,indx] = filterm(lat,lon,Z,R,allowed)
[latout,lonout] = filterm(lat,lon,Z,R,allowed) filters
a set of latitudes and longitudes to include only those data points
which have a corresponding value in
Z equal to
be a geographic raster reference object, a referencing vector, or
a referencing matrix.
R is a geographic raster reference object,
RasterSize property must be consistent with
R is a referencing vector, it must be
a 1-by-3 with elements:
[cells/degree northern_latitude_limit western_longitude_limit]
R is a referencing matrix, it must be
3-by-2 and transform raster row and column indices to or from geographic
coordinates according to:
[lon lat] = [row col 1] * R
R is a referencing matrix, it must define
a (non-rotational, non-skewed) relationship in which each column of
the data grid falls along a meridian and each row falls along a parallel.
Nearest-neighbor interpolation is used by default. NaN is returned
for points outside the grid limits or for which
NaN. All angles are in units of degrees.
[latout,lonout,indx] = filterm(lat,lon,Z,R,allowed) also
returns the indices of the included points.
Filter a random set of 100 geographic points. Use the
Then generate 100 random points:
lat = -90+180*rand(100,1); long = -180+360*rand(100,1);
Make a land map, which is
land = topo>0; [newlat,newlong] = filterm(lat,long,land,topolegend,1); size(newlat) ans = 15 1
15 of the 100 random points fall on land.