MagicPlot Manual

Plotting and nonlinear fitting software

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relnotes:notes27 [Fri Jul 1 21:57:33 2016]
Alexander
relnotes:notes27 [Wed Aug 1 20:46:45 2018] (current)
Alexander
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 ===== A Correction in Chi Square Calculation if Y Errors are Set ===== ===== A Correction in Chi Square Calculation if Y Errors are Set =====
  
-In nonlinear fitting algorithm in MagicPlot 2.5.1 and older, if Y error column(s) were set, weights of points were normalized so that the sum of weights was equal to one. The resulting chi square value shown in 'fit report' in old releases did not take into account real Y error amplitudes. In MagicPlot 2.7 the points weights are not normalized and chi square is calculated correctly. Note that this modification does not affect the resulting fit parameter values and standard deviations which were correct in old releases. See also: [[:fit_formulas]].+In nonlinear fitting algorithm in MagicPlot 2.5.1 and older, if Y error column(s) were set, weights of points were normalized so that the sum of weights was equal to one. The resulting chi square value shown in the 'fit report' tab in old releases did not take into account the real Y error amplitudes. In MagicPlot 2.7 the point weights are not normalized and the chi square is calculated correctly. Note that this modification does not affect the resulting fit parameter values and standard deviations which were calculated correctly in all releases. See also: [[:fit_formulas]].
  
 [[http://magicplot.com/downloads.php|Download MagicPlot]] [[http://magicplot.com/downloads.php|Download MagicPlot]]
  
relnotes/notes27.1467399453.txt.gz ยท Last modified: Fri Jul 1 21:58:04 2016 (external edit)