This example then specifies a smoothed spline interpolation method on the GRID statement. As shown by the following output, the resulting surface plot is smoother still. libname reflib ...

SIAM Journal on Numerical Analysis, Vol. 8, No. 1 (Mar., 1971), pp. 67-74 (8 pages) It is shown that if x ∈ C4[a, b] is approximated by a natural cubic spline, then ...

libname reflib 'SAS-data-library'; goptions reset=global gunit=pct border cback=white colors=(black blue green red) ftext=swiss ftitle=swissb htitle=6 htext=3; title 'Surface Plot after Partial ...