findm (Mapping Toolbox)

Find latitude and longitude coordinates for nonzero map entries

Syntax

[lat,lon] = findm(map,maplegend)
[lat,lon,val] = findm(map,maplegend)
[lat,lon,val] = findm(latin,lonin,map)
mat = findm(...)

Description

This function works in two modes: with a regular matrix restriction and without.

[lat,lon] = findm(map,maplegend) returns latitude and longitude vectors lat and lon, which provide the locations of all nonzero entries of the regular matrix map, map, with three-element map legend vector maplegend.

[lat,lon,val] = findm(map,maplegend) also returns the values, val, of the matrix map corresponding to the lat and lon locations.

[lat,lon,val] = findm(latin,lonin,map) removes the regular matrix restriction. Two matrices, latin and lonin, the same size as map, must provide cell-by-cell latitude and longitude coordinates matched with the corresponding entries of map.

mat = findm(...) returns a single output mat of the form [lat,lon].

Examples

The entered map can also be the result of a logical statement. Where is elevation greater than 5500 meters?

load topo
mat = findm((topo>5500),topolegend)
mat =
   34.5000   79.5000
   34.5000   80.5000
   30.5000   84.5000
   28.5000   86.5000

These points are in the Himalayas.