function?[N]?=?basisfunction（n?npts?u?t）
%?Evaluate?basis?function?at?specified?u.
%
%?Input?arguments:
%?n:
%????NURBS?order?（2?for?linear?3?for?quadratic?4?for?cubic?etc.）
%?npts:
%????number?of?control?points
%?u:
%????point?to?evaluate
%?t:
%????knot?vector
%
%?Output?arguments:
%?N:
%???vector?with?size?npts?containing?value?of?the?basis?function?at?u

%Written?by?Graziano?Fuccio?email:?g.fuccio359@gmail.com
nplusc?=?npts?+?n;
N?=?zeros（npts）;

for?i?=?1:?nplusc?-?1
????if?u?>=?t（i）?&&?u?<=?t（i+1）
????????N（i）?=?1;
????else
????????N（i）?=?0;
????end
end

%application?of?the?formula?that?you?can?find?on?the?NURBS?book
for?k?=?2?:?n
????for?i?=?1?:?nplusc?-?k
????????if?N（i）?~=?0
????????????d?=?（（u?-?t（i））?*?N（i））?/?（t（i?+?k?-?1）?-?t（i））;
????????else
????????????d?=?0;
????????end
????????if（N（i?+?1）?~=?0）
????????????e?=?（（t（i?+?k）?-?u）?*?N（i?+?1））?/?（t（i?+?k）?-?t（i?+?1））;
????????else
????????????e?=?0;
????????end
????????N（i）?=?d?+?e;
????end
end

N?=?N（:?1）;
N?=?N‘;

end

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????1056??2016-11-29?21:37??basisfunction.m
?????文件????????2770??2016-11-29?21:39??nurbsfun.m
?????文件?????????577??2016-11-29?21:44??nurbs_example.m
?????文件????????1315??2016-11-29?09:16??license.txt