GEOMETRIE DES KREISES; ELLIPTIC CURVES (ALGEBRAIC GEOMETRY); Singular value decomposition; Least squares; ELLIPTISCHE KURVEN (ALGEBRAISCHE GEOMETRIE); PROGRAMS AND ALGORITHMS FOR THE SOLUTION OF SPECIAL PROBLEMS; Curve fitting; METHODEN DER KLEINSTEN QUADRATE (NUMERISCHE MATHEMATIK); GEOMETRY OF THE CIRCLE; LEAST SQUARES COMPUTATIONS (NUMERICAL MATHEMATICS); PROGRAMME UND ALGORITHMEN ZUR LÖSUNG SPEZIELLER PROBLEME