4.1.9 Quick Sigmoidal Fit Gadget


Summary

The Quick Sigmoidal Fit gadget can be used to quickly perform a sigmoidal fit on a portion of your graph that you define interactively as your region of interest (ROI).

Minimum Origin Version Required: Origin 2015 SR0

What you will learn

  • How to use the Quick Sigmoidal Fit gadget on a graph.
  • How to select your fitting options.
  • How to switch to the NLFit dialog.
  • How to output the fitting result.
  • How to find X/Y values on the fit curve.

Steps

This tutorial is associated with <Origin EXE Folder>\Samples\Tutorial Data.opj.

Quick Fit

  1. Open Tutorial Data.opj and browse to the Quick Sigmoidal Fit Gadget folder in Project Explorer (PE).
  2. Highlight Col(A) through Col(D) in the workbook DoseResponseN and from the menu choose Plot:Symbol:Scatter to plot a scatter graph.
    Quick Sigmoidal Fit Gadget 01.png
  3. Double-click the X axis to open Axis dialog. In the Scale tab, set the Type as Log10 and click OK button to close the dialog.
    Quick Sigmoidal Fit Gadget 02.png
  4. Click the Rescale button Rescale button.png to show the plot with the proper scale.
    Quick Sigmoidal Fit Gadget 03.png
  5. Select Gadgets: Quick Sigmoidal Fit... from the main menu to open the addtool_sigmoidal_fit dialog box. Select the function Logistic5 from the Function drop-down list on the Settings tab.
    Quick Sigmoidal Fit Gadget 04.png
  6. Click the ROI Box tab and uncheck the parameters x0, h, and s under the Parameter List branch.
    Quick Sigmoidal Fit Gadget 05.png
  7. Click the Fit Curve tab, select Mean, SD from the Plot Type drop-down list and Source Book, New Sheet from the Output Fit Curve To drop-down list.
    Quick Sigmoidal Fit Gadget 06.png
  8. Click OK to add the ROI box to the graph. At the top right corner of the ROI box, click the Arrow button Triangle button.png to select Expand to the Full Plots Range from the menu. The ROI box will cover the full data range on the graph.
    Quick Sigmoidal Fit Gadget 07.png
  9. Click the arrow button Triangle button.png again to select Preferences... from the menu. This opens the Sigmodial Fit Preferences dialog box. In this dialog, click the Report tab and set Output To as None.
    Quick Sigmoidal Fit Gadget 08.png
  10. Click OK to close the dialog box. Click the arrow button Triangle button.png to select Change Function: Logistic and change the fitting function to Logistic. The label text on top of the ROI box will update automatically.
    Quick Sigmoidal Fit Gadget 09.png
  11. Click the arrow button Triangle button.png to select New Output and output the fitting result to the worksheet and graph.
    Quick Sigmoidal Fit Gadget 10.png

Connect to NLFit

When using the Quick Sigmoidal Fit gadget you can easily switch to the NLFit tool. This makes it easy to get a detailed fit report using the current fitting settings in the gadget.

  1. Redo step 1 through step 8 as shown above.
  2. Click the arrow button Triangle button.png to select Switch to NLFit... to open the NLFit dialog with the inherited settings.
    Quick Sigmoidal Fit Gadget 11.png
    Quick Sigmoidal Fit Gadget 12.png
  3. Click the Fit button to perform curve fitting. The results are output to the result sheets and the source graph.
    Quick Sigmoidal Fit Gadget 13.png

Find X/Y

With his gadget you can also quickly find X/Y values on the fitted curve.

  1. Redo step 1 through step 8 as shown in the first section.
  2. Click the arrow button Triangle button.png to select Find X/Y... from the menu to open the Find X/Y dialog.
    Quick Sigmoidal Fit Gadget 14.png
  3. Select the Worksheet radio box and enter 40;45;50 for Y, then click Find X to show the corresponding X values in the empty X box. Then, click the Output button and the X and Y values are output to the specified worksheet.
    Quick Sigmoidal Fit Gadget 15.png
  4. Click the Go button beside the Worksheet radio box to open the Find X/Y workbook. Click the Close button to close the Find X/Y dialog.
    Quick Sigmoidal Fit Gadget 16.png