Convexity and positivity of bivariate quadratic Bézier surfaces over a rectangle

Autor: You-dong Ding
Rok vydání: 2001
Předmět:
Zdroj: Journal of Shanghai University (English Edition). 5:20-28
ISSN: 1863-236X
1007-6417
Popis: With the help of several discriminants about the zero points of a quartic polynomial, the sufficient and necessary conditions for the positivity and nonnegativity of the quartic polynomial over an interval I⊂(−∞, +∞) was derived. Based on these conclusions, the sufficient and necessary conditions for the positivity and convexity of the 2×2 Bezier surface over a rectangle were obtained. A simple sufficient condition was deduced also and finally several examples were given.
Databáze: OpenAIRE