------ + ------- - ------- + ----) charfun2(x, 3, 6)
       4932       274      1644     274

(%i4) f(x):=''%$
(%i5) /* Some evaluations */
      map(f,[2.3,5/7,%pi]), numer;
(%o5) [1.991460766423356, 5.823200187269903, 2.227405312429507]
(%i6) load(draw)$  /* load draw package */
(%i7) /* Plotting interpolating function */
      draw2d(
        color      = red,
        key        = &quot;Cubic splines&quot;,
        explicit(f(x),x,0,10),
        point_size = 3,
        color      = blue,
        key     