Abstract
This note is dedicated to the study ofS m , the set of (α,β) for which the interpolatory quadrature formula based on the zeroes ofP (α,β)(t) m has positive weights. In contract to the results published by Lether, Wilhelmsen and Frazier [5], we show thatS m behaves very regularly. The point is that the casesm odd andm even must be distinguished. Furthermore, informations on the exact number of negative weights for values outside ofS m are obtained.
Zusammenfassung
Wir definieren mitS m die Menge der Werte (α, β), für welche die Interpolationsquadraturformel basierend auf den Nullstellen vonP (α, β) m (t) positive Gewichte besitzt. Im Gegensatz zu den Resultaten von Lether, Wilhelmsen und Frazier [5] zeigen wir, daßS m sich sehr regelmäßig verhält. Zu diesem Zweck ist es notwendig, die Fällem gerade undm ungerade zu unterscheiden. Weiters erhalten wir Informationen über die exakte Anzahl der negativen Gewichte außerhalb vonS m .
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Sottas, G. On the positivity of quadrature formulas with Jacobi abscissas. Computing 29, 83–88 (1982). https://doi.org/10.1007/BF02254853
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DOI: https://doi.org/10.1007/BF02254853