Mercurial > hg > octave-lyh
diff scripts/polynomial/spline.m @ 14104:614505385171 stable
doc: Overhaul docstrings for polynomial functions.
* mkpp.m, mpoles.m, pchip.m, poly.m, polyaffine.m, polyder.m, polyfit.m,
polygcd.m, polyint.m, polyout.m, polyreduce.m, polyval.m, polyvalm.m, ppder.m,
ppval.m, residue.m, roots.m, spline.m, unmkpp.m: Improve docstrings.
author | Rik <octave@nomad.inbox5.com> |
---|---|
date | Fri, 23 Dec 2011 20:09:27 -0800 |
parents | 59e2460acae1 |
children | 72c96de7a403 |
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--- a/scripts/polynomial/spline.m +++ b/scripts/polynomial/spline.m @@ -20,23 +20,22 @@ ## -*- texinfo -*- ## @deftypefn {Function File} {@var{pp} =} spline (@var{x}, @var{y}) ## @deftypefnx {Function File} {@var{yi} =} spline (@var{x}, @var{y}, @var{xi}) +## Return the cubic spline interpolant of points @var{x} and @var{y}. +## +## When called with two arguments, return the piecewise polynomial @var{pp} +## that may be used with @code{ppval} to evaluate the polynomial at specific +## points. When called with a third input argument, @code{spline} evaluates +## the spline at the points @var{xi}. The third calling form @code{spline +## (@var{x}, @var{y}, @var{xi})} is equivalent to @code{ppval (spline +## (@var{x}, @var{y}), @var{xi})}. ## -## Return the cubic spline interpolant of @var{y} at points @var{x}. -## If called with two arguments, @code{spline} returns the piecewise -## polynomial @var{pp} that may later be used with @code{ppval} to -## evaluate the polynomial at specific points. -## If called with a third input argument, @code{spline} evaluates the -## spline at the points @var{xi}. There is an equivalence -## between @code{ppval (spline (@var{x}, @var{y}), @var{xi})} and -## @code{spline (@var{x}, @var{y}, @var{xi})}. -## -## The variable @var{x} must be a vector of length @var{n}, and @var{y} -## can be either a vector or array. In the case where @var{y} is a -## vector, it can have a length of either @var{n} or @code{@var{n} + 2}. -## If the length of @var{y} is @var{n}, then the 'not-a-knot' end -## condition is used. If the length of @var{y} is @code{@var{n} + 2}, -## then the first and last values of the vector @var{y} are the values -## of the first derivative of the cubic spline at the end-points. +## The variable @var{x} must be a vector of length @var{n}. @var{y} can be +## either a vector or array. If @var{y} is a vector it must have a length of +## either @var{n} or @code{@var{n} + 2}. If the length of @var{y} is +## @var{n}, then the "not-a-knot" end condition is used. If the length of +## @var{y} is @code{@var{n} + 2}, then the first and last values of the +## vector @var{y} are the values of the first derivative of the cubic spline +## at the endpoints. ## ## If @var{y} is an array, then the size of @var{y} must have the form ## @tex @@ -52,7 +51,7 @@ ## @ifnottex ## @code{[@var{s1}, @var{s2}, @dots{}, @var{sk}, @var{n} + 2]}. ## @end ifnottex -## The array is then reshaped internally to a matrix where the leading +## The array is reshaped internally to a matrix where the leading ## dimension is given by ## @tex ## $$s_1 s_2 \cdots s_k$$ @@ -61,9 +60,10 @@ ## @code{@var{s1} * @var{s2} * @dots{} * @var{sk}} ## @end ifnottex ## and each row of this matrix is then treated separately. Note that this -## is exactly the opposite treatment than @code{interp1} and is done -## for compatibility. -## @seealso{ppval, mkpp, unmkpp} +## is exactly opposite to @code{interp1} but is done for @sc{matlab} +## compatibility. +## +## @seealso{pchip, ppval, mkpp, unmkpp} ## @end deftypefn ## This code is based on csape.m from octave-forge, but has been