Automatic Curve Fit

The Automatic curve fit will fit one of a list of functions to the selected region of a graph or table window. Logger Pro chooses the best fit using a least-squares approach. The Mean Square Error is the sum of the distance squared of the difference between the fitted line and the data points, divided by the number of data points. The curve with the smallest Mean Square Error is the one chosen.

A tutorial covering curve fitting is available. To access it, choose Open from the File menu. Open the Experiments folder, then the Tutorials folder.

  1. To perform an Automatic curve fit, highlight the region of interest by clicking and dragging the mouse across the graph.
  2. Click the Curve Fit button A curve fit button image on the toolbar or choose Curve Fit from the Analyze menu. If multiple columns have been graphed, choose the appropriate column from the list.
  3. Ensure that the Fit Type is set to Automatic. Note: If Automatic Fit Type is disabled, make sure that Allow Automatic Curve Fit is enabled in the Preferences dialog.
  4. Select the General Equation you wish to examine and click Try Fit. Coefficients are automatically applied, but can be adjusted. In you adjust the coefficients, the Fit Type will change to Manual. To apply other curve fit equations, select the function and click Try Fit.
  5. Click Done to close the dialog box. The Curve Fit box containing the equation and fit coefficients of the fitted function will be displayed the graph.

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