MagicPlot Manual

Plotting and nonlinear fitting software

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fit_formulas

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fit_formulas [Fri Jul 1 13:31:51 2016]
Alexander
fit_formulas [Tue May 30 16:28:13 2017] (current)
Alexander
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   * //f//(//x, β<​sub>​1</​sub>,​...,​β<​sub>​p</​sub>//​) is the fit function which depends on value of //x// and fit parameters //​β<​sub>​k</​sub>//,​   * //f//(//x, β<​sub>​1</​sub>,​...,​β<​sub>​p</​sub>//​) is the fit function which depends on value of //x// and fit parameters //​β<​sub>​k</​sub>//,​
   * //p// is the number of fit parameters //​β<​sub>​k</​sub>//, ​   * //p// is the number of fit parameters //​β<​sub>​k</​sub>//, ​
-  * //​w<​sub>​i</​sub>//​ are normalized (Σ//​w<​sub>​i</​sub>//​ = 1) data weighting coefficients for each point (//​x<​sub>​i</​sub>,​ y<​sub>​i</​sub>//​).+  * //​w<​sub>​i</​sub>//​ are data weighting coefficients for each point (//​x<​sub>​i</​sub>,​ y<​sub>​i</​sub>//​).
  
 An initial guess for the parameters has to be provided to start minimization. Calculation of the new guess of parameters on each fit iteration is based on the fit function partial derivatives for current values of fit parameters for each //x// value: An initial guess for the parameters has to be provided to start minimization. Calculation of the new guess of parameters on each fit iteration is based on the fit function partial derivatives for current values of fit parameters for each //x// value:
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 MagicPlot can use weighting of //y// values based on y errors //​s<​sub>​i</​sub>//:​ MagicPlot can use weighting of //y// values based on y errors //​s<​sub>​i</​sub>//:​
  
-  * If standard //y// errors //​s<​sub>​i</​sub>//​ are specified: //​w<​sub>​i</​sub>//​ = 1 / //​s<​sub>​i</​sub><​sup>​2</​sup>//;​+  * If standard //y// errors //​s<​sub>​i</​sub>//​ are specified: //​w<​sub>​i</​sub>//​ = 1 / //​s<​sub>​i</​sub><​sup>​2</​sup>// ​((Corrected in MagicPlot 2.7: weights //​w<​sub>​i</​sub>//​ are not normalized anymore. In MagicPlot 2.5.1 and earlier the sum of weights was normalized to 1. This changing only affects the resulting Chi square value in the fit report if Y error column(s) are set.));
   * Otherwise: all //​w<​sub>​i</​sub>//​ = 1.   * Otherwise: all //​w<​sub>​i</​sub>//​ = 1.
  
fit_formulas.1467369111.txt.gz · Last modified: Fri Jul 1 13:32:22 2016 (external edit)