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fit_formulas [Sun Nov 8 12:21:24 2015] 127.0.0.1 external edit |
fit_formulas [Tue May 30 16:28:13 2017] (current) Alexander |
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* //f//(//x, β< | * //f//(//x, β< | ||
* //p// is the number of fit parameters // | * //p// is the number of fit parameters // | ||
- | * // | + | * // |
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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===== Weighting of Data Points Using Y Errors ===== | ===== Weighting of Data Points Using Y Errors ===== | ||
MagicPlot can use weighting of //y// values based on y errors // | MagicPlot can use weighting of //y// values based on y errors // | ||
- | * If standard //y// errors are **not** specified: all // | ||
- | * If standard //y// errors // | ||
- | <m>w_i=C 1/{{s_i}^2}</m> | + | * If standard //y// errors //s<sub>i</ |
- | + | * Otherwise: all //w<sub>i</sub>// = 1. | |
- | here //C// is normalizing coefficient | + | |
- | + | ||
- | <m>C=N sum{i=1}{N}{{s_i}^2}</m> | + | |
In '' | In '' | ||
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Because of some confusion in the names of the parameters in different sources (books and software), we also give many different names of same parameter in //note// column. | Because of some confusion in the names of the parameters in different sources (books and software), we also give many different names of same parameter in //note// column. | ||
+ | |< 100% 15% 10% 45% 30% >| | ||
^ Parameter Name ^ Symbol | ^ Parameter Name ^ Symbol | ||
^ Original Data and Fit Model Properties | ^ Original Data and Fit Model Properties |