The primary purpose of TSPACK is to construct a smooth function which
interpolates a discrete set of data points. The function may be requir
ed to have either one or two continuous derivatives. If the accuracy o
f the data does not warrant interpolation, a smoothing function (which
does not pass through the data points) may be constructed instead. Th
e fitting method is designed to avoid extraneous inflection points (as
sociated with rapidly varing data values) and preserve local shape pro
perties of the data (monotonicity and convexity), or to satisfy the mo
re general constraints of bounds on function values or first derivativ
es. The package also provides a parametric representation for construc
ting general planar curves and space curves.