Piecewise Monotone Quadratic Histosplines

Abstract

A method is presented for constructing a quadratic spline function satisfying area-matching conditions and local monotonicity constraints, according to the frequencies on the class intervals and to the shape of a given histogram. Such a function is “as close as possible” to the quadratic spline that satisfies the area-matching conditions and the minimum curvature property and generally exhibits a visually pleasing graph.