Curve fitting When data is given for discrete values a long continuum , we may require estimates at points between the discrete values. Curve are fitted to such data obtain intermediate estimates it is also used to replace a complicated function. 1. Least –Square –Regression. 2. Interpolation.
Least- squares regression F(X) Used for data that exhibitions noise error. (does not intersect every point ) X
Interpolation Used for very precise data when curve passes directly through each points The values between points are estimated
Types of Interpolation F(x) The first type is : Linear Interpolation x
Types of Interpolation F(X) Interpolation The second type is : Curvilinear Interpolation Extrapolation X Extrapolation : Goes beyond limits of the data. Interpolation : Goes within limits of the data
Statistics Review 1. Arithmetic Mean ( ): Is the location of the center of the distribution of the data. Sum of in divided data points Number of points
2. Standard derivation ( ): Is a measure of spread for sample a bout the mean Total sum of the squares of the residuals between data points and the mean
2. Variance ( ): Degree of freedom If (n-1) values are know , the remaining value is known also:
3. Coefficient of Variation (C. V): It is a normalized measure of the spread.