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This comprehensive course covers Exact Fit, Interpolation, Extrapolation, Approximation, Weierstrass Approximation Theorem, Error Analysis, Lagrange Interpolating Polynomial, Divided Differences, Newton’s Interpolating Polynomials, Forward Difference Interpolating Polynomials, Error Analysis, Multivariate Function Interpolation, Inverse Interpolation, Spline Interpolation, and Cubic Spline Interpolation. Dive into the world of numerical analysis and sharpen your skills in fitting functions accurately.
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Numerical Analysis –Interpolation Hanyang University Jong-Il Park
Fitting • Exact fit • Interpolation • Extrapolation • Approximate fit Extrapolation x Interpolation x x x x
Approximation error Better approximation
Illustration of Lagrange polynomial • Unique • Too much complex
Differences • Difference • Forward difference : • Backward difference : • Central difference : f
Divided Differences ; 1st order divided difference ; 2nd order divided difference
Newton’s Forward Difference Interpolating Polynomials(I) • Equal Interval h • Derivation n=1 n=2
Newton’s Forward Difference Interpolating Polynomials(II) Generalization • Error Analysis Binomial coef.
1 1 Intpl. of Multivariate Function • Successive univariate polynomial • Direct mutivariate polynomial 2 direct multivariate Successive univariate
Inverse Interpolation = finding x(f) • Utilization of Newton’s polynomial Solve for x 1st approximation 2nd approximation Repeat until a convergence
spline polynomial Spline Interpolation • Why spline? Linear spline Quadratic spline Cubic spline Continuity • Good approximation !! • Moderate complexity !!
Cubic spline interpolation(I) • Cubic Spline Interpolation at an interval 4 unknowns for each interval 4n unknowns for n intervals Conditions 1) 2) 3) continuity of f’ 4) continuity of f’’ n n n-1 n-1
Cubic spline interpolation(II) • Determining boundary condition Method 1 : Method 2 : Method 3 :
Eg. CG modeling Non-Uniform Rational B-Spline