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
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Description
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MSE
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Mean Square Error
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R2
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R2 - 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.
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SS
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The sum of the squares of the residuals (errors)
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SYX
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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.
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Output Variables specific to the fit are also available as follows:
Fit Method
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Output Variables
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Details
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Linear Regression
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m
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The slope
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c
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The intercept
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Polynomial Fit
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a, b, c, d, e, f, g, h, i, j
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Letters a-j depending on the specified order representing the determined coefficients
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Four Parameter Fit
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a, b, c, d
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The determined four parameter coefficients. c is the centre point.
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Five Parameter Fit
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a, b, c, d, m
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The determined five parameter coefficients. c is the centre point and m is a measure of symmetry about c
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Cubic Spline
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There are no output variables produced for the cubic spline.
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Michaelis-Menten
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Vmax
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The determined maximum value of y.
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Km
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The determined Michaelis-Menten coefficient.
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Exponential
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Y0
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Y intercept
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V0
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Initial down-slope
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K
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Decay-rate constant
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 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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