Which output variables are available from the curve fits?Document ID: DQ236 Relevant to following products: WorkOut 2.0 Manta Document description: Which output variables are available from the curve fits?
Curve fit transforms result in Output Variables; these hold further information about the fit.
The following output variables are produced by all fit methods to quantify the goodness of the fit:
Output Variables

Description

MSE

Mean Square Error

R2

R^{2}  this is 1 minus the ratio of SS / (the sum of the squares of the differences between Y fit and the mean Y value). This will equal 1 for a good fit (SS = 0) and tend towards 0 for a bad fit.

SS

The sum of the squares of the residuals (errors)

SYX

The standard deviation of the residuals. This is the square root of (the sum of the squares of the residuals divided by (number of data points – number of coefficients)). This will not be calculated if the number of data points is equal to the number of coefficients.

Output Variables specific to the fit are also available as follows:
Fit Method

Output Variables

Details

Linear Regression

m

The slope

c

The intercept

Polynomial Fit

a, b, c, d, e, f, g, h, i, j

Letters aj depending on the specified order representing the determined coefficients

Four Parameter Fit

a, b, c, d

The determined four parameter coefficients. c is the centre point.

Five Parameter Fit

a, b, c, d, m

The determined five parameter coefficients. c is the centre point and m is a measure of symmetry about c

Cubic Spline

There are no output variables produced for the cubic spline.

MichaelisMenten

Vmax

The determined maximum value of y.

Km

The determined MichaelisMenten coefficient.

Exponential

Y0

Y intercept

V0

Initial downslope

K

Decayrate constant

Related articles: DQ234: How To: Access the Standard Curve Fit parameters. How To: Access the Standard Curve Fit parameters.
DQ235: How To: Access the Kinetic Fit parameters How To: Access the Kinetic Fit parameters
DQ073: What is Rē? What is Rē?
DQ074: What is SS? What is SS?
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