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Home Programming DataLab DLabPascal Mathematical Functions Curve Fitting Methods CalcLinFit
See also: StdDevX, CalcAnovaReg, CalcStatistics, CalcGaussFit, CalcLogFit, TheilSenEstimator, CalcRegModel 

CalcLinFit

Declaration:TCurveFit.CalcLinFit (var k, d, FitQual: Double);
The procedure CalcLinFit estimates the best fit of a straight line to a sample of two-dimensional data points using linear regression. The line is defined by the equation

y = kx + d.

The data points have to be entered by using the procedure EnterStatValue. A minimum number of 2 values is required in order to apply CalcLinFit. Do not forget to reset the statistics calculation before entering any new datasets (use Init)

The procedure CalcLinFit returns the following parameters: k and d define the slope and the offset of the line, and FitQual returns the goodness of fit of the regression. FitQual equals the square of the correlation coefficient. A good representation of the data samples yields a value near to 1.0 for FitQual.

Hint: The quality of fit calculated by CalcLinFit is not adjusted for the degree of freedoms in the regression parameters.