Latitudes and longitudes of nonzero data grid elements
[lat,lon] = findm(Z,R)
[lat,lon] = findm(latz,lonz,Z)
[lat,lon,val] = findm(...)
mat = findm(...)
[lat,lon] = findm(Z,R) computes
the latitudes and longitudes of the nonzero elements of a regular
R can 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.
[lat,lon] = findm(latz,lonz,Z) returns
the latitudes and longitudes of the nonzero elements of a geolocated
Z, which is an M-by-N logical or numeric
M-by-N latitude-longitude arrays, but
be a latitude vector of length M and
lonz may be
a longitude vector of length N.
[lat,lon,val] = findm(...) returns
the values of the nonzero elements of
Z, in addition
to their locations.
mat = findm(...) returns
a single output, where
mat = [lat lon].
This function works in two modes: with a regular data grid and with a geolocated data grid.
The data grid can be the result of a logical operation. For instance, you can find all locations with elevations greater than 5500 meters.
load topo topoR = refvecToGeoRasterReference(topolegend,size(topo)); [lat,lon] = findm((topo>5500),topoR); [lat lon] ans = 34.5000 79.5000 34.5000 80.5000 30.5000 84.5000 28.5000 86.5000
These points are in the Himalayas. Find the grid values at these locations using
[row,col] = geographicToDiscrete(topoR,lat,lon); indx = sub2ind(size(topo),row,col); heights = topo(indx) heights = 5559 5515 5523 5731