Recently, in [Electronic Transaction on Numerical Analysis, 41 (2014), pp.
420-442] authors introduced a new class of rational cubic fractal interpolation
functions with linear denominators via fractal perturbation of traditional
nonrecursive rational cubic splines and investigated their basic shape
preserving properties. The main goal of the current article is to embark on
univariate constrained fractal interpolation that is more general than what was
considered so far. To this end, we propose some strategies for selecting the
parameters of the rational fractal spline so that the interpolating curves lie
strictly above or below a prescribed linear or a quadratic spline function.
Approximation property of the proposed rational cubic fractal spine is broached
by using the Peano kernel theorem as an interlude. The paper also provides an
illustration of background theory, veined by examples.Comment: 7 pages, 6 figure