ABSTRACT
Considerable attention has been paid recently to so-called histosplines which match a given area between two consecutive knots. They may be regarded as smooth approximations of a histogram which is a graph of a piecewise defined constant function and may also be called area matching splines. In particular, J. W. Schmidt and coworkers have contributed to this field. Also constraints of various types have been taken into account. For recent references con sult Schmidt & Hefi [1993]. However, Schmidt and coworkers usually used splines from a certain prescribed class like cubic splines and tried to give as much smoothness as possible subject to the constraints considered. The unconstrained histosplines were already investigated by Schoenberg [1973].
