Calculate polynomial coefficients from all polynomial data points using matrix factorisation.
Enter data as comma separated pairs (X,Z), with each pair on a new line, or copy and past cells from a spreadsheet. The data should be in ascending order.
The polynomial value, slope and curvature are calculated at either the user defined X, the root or zero, the maximum or minimum, or the point of inflection. The maximum and minimum can only be calculated for polynomials of second order or greater. The point of inflection can only be calculated for polynomials of third order or greater. The root, maximum or minimum, or point of inflection must be real.
The user defined Xu value is used as the initial guess value for calculating the root and other points. Use the Result Plot option to plot the polymomial value, slope and curvature versus X, and to determine suitable guess values for Xu.
Tool Input
- ptype : Polynomial Calculation Type
- Xu : User Defined X Value or Guess Value
- Xdata : X Data Values
- Zdata : Z Data Values
Tool Output
- C : Polynomial Curvature At X
- P : Polynomial Value At X
- S : Polynomial Slope At X
- X : X Value (Input, Root, Maximum or Minimum, Or Inflection Point)
- cvg : Convergence (== 1)
- |M| : Matrix Determinant (!= 0)