"David Epstein" <David.Epstein.spam@remove.warwick.ac.uk> wrote in message <lka0n3$6vv$1@newscl01ah.mathworks.com>...
> Question 3. In the documentation for spap2 I found
> "sp = spap2(augknt([a,xi,b],4),4,x,y)
> is the least-squares approximant to the data x, y, by cubic splines with two continuous derivatives."
> So Mathworks thinks that cubic splines have order 4. But the spline community thinks that cubic splines have order 3. Or am I misunderstanding?
You misunderstand here.
Order, degree, who cares? What's in a name? That which we
call a cubic polynomial by any other name would smell as
sweet. Mayhaps I should have been a poet.
They all use cubic polynomials.
John
> Question 3. In the documentation for spap2 I found
> "sp = spap2(augknt([a,xi,b],4),4,x,y)
> is the least-squares approximant to the data x, y, by cubic splines with two continuous derivatives."
> So Mathworks thinks that cubic splines have order 4. But the spline community thinks that cubic splines have order 3. Or am I misunderstanding?
You misunderstand here.
Order, degree, who cares? What's in a name? That which we
call a cubic polynomial by any other name would smell as
sweet. Mayhaps I should have been a poet.
They all use cubic polynomials.
John