Mercurial > octave
changeset 26200:33e6ab3e1491
mkpp.m: Document how ppval will calculate values for each piecewise section (patch #9095).
* mkpp.m: Add Programming Note to documentation explaining how the lower bound
of the piecewise segment will be subtracted from the value of the polynomial
calculated for that segment.
| author | Rik <rik@octave.org> |
|---|---|
| date | Mon, 10 Dec 2018 21:41:39 -0800 |
| parents | 704cd93ca748 |
| children | 750a6f9957ea |
| files | scripts/polynomial/mkpp.m |
| diffstat | 1 files changed, 4 insertions(+), 0 deletions(-) [+] |
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--- a/scripts/polynomial/mkpp.m Mon Dec 10 17:23:17 2018 -0800 +++ b/scripts/polynomial/mkpp.m Mon Dec 10 21:41:39 2018 -0800 @@ -42,6 +42,10 @@ ## @var{r}-th polynomial defined on interval @var{i}. In any case @var{coefs} ## is reshaped to a 2-D matrix of size @code{[@var{ni}*prod(@var{d}) @var{m}]}. ## +## Programming Note: @code{ppval} evaluates polynomials at +## @code{@var{xi} - @var{breaks}(i)}, i.e., it subtracts the lower endpoint of +## the current interval from @var{xi}. This must be taken into account when +## creating piecewise polynomials objects with @code{mkpp}. ## @seealso{unmkpp, ppval, spline, pchip, ppder, ppint, ppjumps} ## @end deftypefn