Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and...

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Lecture 4 - 11.02.2016 B-splines Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) Today: More B-spline properties (2.2-2.4) We will study the B-splines in the expression

Transcript of Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and...

Page 1: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

Lecture 4 - 11.02.2016

B-splines

• Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1)• Today: More B-spline properties (2.2-2.4)

We will study the B-splines in the expression

Page 2: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

B-splines, basic properties

Page 3: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

Spline functions

p=1 and t=(0,0,1,2,4,7,8,9,9)

Page 4: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

Quadratic splines

Variation diminishing spline approximation

(t*3,f(t*3))

s(x)

Page 5: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

B-spline control polygons

Page 6: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

Spline function properties

Page 7: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

Spline curves

Page 8: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

Matrix representations of B-splines (2.3)Linear B-splines on an interval

Recall the recursion formula

Quadratic B-splines on an interval

Page 9: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

Cubic B-splines on an interval

Recall the recursion formula

Page 10: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

General matrix formulation on an interval

Page 11: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

Example

Page 12: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

Evaluation of splines - Alg 2.20

Page 13: Lecture 4 - 11.02.2016 B-splines · Lecture 4 - 11.02.2016 B-splines • Last time: Splines and B-splines (rest pof sec. 1 and sect 2.1) • Today: More B-spline properties (2.2-2.4)

Evaluation of splines - Alg 2.21