Near-algebraic Tchakaloff-like quadrature on spherical triangles

Abstract We present a numerical code for the computation of nodes and weights of a low-cardinality positive quadrature formula on spherical triangles, nearly exact for polynomials of a given degree. The algorithm is based on subperiodic trigonometric gaussian quadrature for planar elliptical sectors and on Caratheodory-Tchakaloff quadrature compression via NNLS.