Spline curve by uniform subdivision
spcrv(c,k) provides a dense sequence
f(tt) of points on the uniform B-spline curve
f of order
k with B-spline coefficients
c. Explicitly, this is the curve
the B-spline with knots a,...,z, and
n the number of coefficients in
spcrv(c) chooses the order
k to be 4.
spcrv(c,k,maxpnt) makes sure that at
maxpnt points are generated. The default value for the
maximum number of sites
tt to be generated is
The parameter interval that the site sequence
tt fills out
uniformly is the interval [
k/2 .. (
The output consists of the array f(tt).
The following would show a questionable broken line and its smoothed version:
points = [0 0 1 1 0 -1 -1 0 0 ; 0 0 0 1 2 1 0 -1 -2]; plot(points(1,:),points(2,:),':') values = spcrv(points,3); hold on, plot(values(1,:),values(2,:)), hold off
Repeated midpoint knot insertion is used until there are at least
maxpnt sites. There are situations where use of
fnplt would be more efficient.