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Spline curve by uniform subdivision
Syntax
spcrv(c) curve = spcrv(c,k,maxpnt)
Description
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
with B(.|a,...,z) the B-spline with knots a,...,z, and n the number of coefficients in c, i.e., [d,n]:=size(c).
The default value for k is 4. The default value for the maximum number of sites tt to be generated is 100.
The parameter interval that the site sequence tt fills out uniformly is the interval [k/2 .. (n-k/2)].
The output consists of the array f(tt).
Examples
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
Algorithm
Repeated midpoint knot insertion is used until there are at least maxpnt sites. There are situations where use of fnplt would be more efficient.
See Also
spcrvdem, fnplt
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