This IOS universal device application has the ability to store multiple datasets, determine a linear or polynomial equation that fits the data, calculate the goodness of fit, graph the given values verses the predicted values and calculate predicted values from the user’s input.
There are two modes of curve fitting: Calibration mode and Standard mode. In the Calibration Mode, an inverse prediction of X (abscissa) from Y (ordinate) is performed. As an example, if x is standard concentration values in mg/L and y is absorbance, then you can predict the concentration in mg/L from any absorbance value. The application derives X in second and third degree polynomials by using equation roots.
The standard mode is available to fit datasets where high degree (up to 9th degree) polynomial fits are required or the Y needs to be predicted from X. Both modes provide the goodness of fit by calculating the correlation coefficient (r^2) and the relative percent difference (RPD) between the measured values and the predicted values.
© © 2018 John Durand