Function [F,nsel] = selecttri(f,iv) returns a new triangular mesh after selecting triangles defined by three vertices from the given list of vertices. Variables f and F have three columns containing the indices to three vertices, representing the three vertices by which a triangle is defined. Input variable iv is a one-dimensional array of indices to vertices. Output variable nsel is the number of selected triangles. The validity of the input is not checked! See also function removetri(). (c) 2026 fabien van mook 2026.08.20 release of this file within package "fvm-geometry" under GNU GPLv3+