15.3 Quick FitQuickFitGadget
Overview
The Quick Fit Gadget allows you to perform linear fitting and nonlinear curve fitting in a flexible and easy way, on data plotted in a graph. The tool creates a ROI (Region of Interest) object with which you can drag and choose a range of the curve to be fitted quickly.
With the Quick Fit Gadget you can:
 Change the fitting data range by simply moving and resizing the ROI
 Maintain a list of favorite fitting functions
 Easily add to favorite functions list from a large selection of builtin fitting functions or userdefined functions
 Display parameter values and/or fit statistics on top of ROI
 Interactively perform multiple fit operations to multiple ranges of same dataset, or to multiple datasets in the graph layer
 Append fit results to a worksheet, for consolidated results from multiple fitting operations
 Launch the advanced NLFit tool using Gadget settings for data range, function, and parameter values
 Find specific/new X/Y values using the fit curve
 Save settings, including function, to a Theme file for repeat use.
To Use Quick Fit Gadget
To use Quick Fit gadget, select from menu Gadgets: Quick Fit when a graph window is active.
Settings tab
Fit Mode

Select either Polynomial Fit or Nonlinear Curve Fit with this dropdown list. After the selection, the corresponding functions will be listed in the Function dropdown list.

Function

You can choose a function with which to perform the fitting. Note that you can add more functions to this list by selecting the <more> option to open the Edit Quick Fit Function List dialog.
Edit Function List
 In this dialog, you can add or remove functions which are listed in the Quick Fit Function List. You can also reorder the function list by dragginganddropping or using the rightclick menu to move up or move down.

Apparent Fit

This check box is only available when the Fit Mode is set to Polynomial Fit.
Specify whether to use the apparent values for fitting, according to the current axis scales. For example, select this box to fit exponentially decaying data with a straight line fit when data are plotted on a log scale.
When this check box is selected and the data has error values associated with it, Origin uses the larger of the positive/negative errors as weight.

 Apparent fitting is only useful when the fitting is started from a graph with nonlinear axes (Log10, for example). If you check this option, the fitter will first transform raw data into a new data space according to the axis types, and then perform the fitting on the transformed data. As you can see, apparent fitting is equivalent to transforming the raw data in worksheet and then applying a direct fitting.

ROI Box tab
Specify the ROI (Region of Interest) settings. The fitting will be performed within the ROI range.
X Scale From

Specify the starting ROI X value.

X Scale To

Specify the ending ROI X value.

Fix(Prevent moving by ROI)

Specify whether to fix the X scale of the ROI box. Once this check box is checked, moving and resizing the ROI box are forbidden.

Show ToolName

Specify whether to show this tool's name on the graph.

Show Rectangle after Fit

Specify whether to show the rectangle over the graph after fitting.

Significant Digits

Specify the significant digits. The default System significant digits can be set in Option dialog. See also: system digits.

Show on CenterTop of ROI Box

Specify the values that will be shown on the centertop of ROI box.

Parameter List

All parameters of the fitting function will be listed in the tree node and you can select them as you need to show them on the centertop of ROI.

Fill Color

Specify the ROI rectangle color.

Fit Curve Color

Specify fitted curve color.

Label Box tab
This tab controls the result text box content that is pasted on the graph.
Add Label Box to Graph

Specify if you want to paste the result text box to the source graph.

Significant Digits

Specify the significant digits. The option System mean using the settings set in Option dialog. See also: system digits.

Function

Specify whether to show the fitting function name.

Input

Specify whether to show the name of the input dataset in the Label Box. Options include:
 None
 Do not show the name of the input dataset.
 [Book]Sheet!Short Name
 Show the name of the input dataset as [Book]Sheet!Short Name.
 [Book]Sheet!Long Name
 Show the name of the input dataset as [Book]Sheet!Long Name.
 Long Name only
 Only show the long name of the input dataset.
 Plot Legend
 Show as the Legend of the plot.

Range

Specify whether to show the range of the input dataset in the Label Box. Options include:
 None
 Do not show the range.
 Indices
 Use the indices to identify the range of the input dataset.
 X Values
 Use the X values to identify the range of the input dataset.

Output

Specify whether to show the name of the fitted dataset in the Label Box.
 None
 Do not show the name of the fitted dataset.
 [Book]Sheet!Short Name
 Show the name of the fitted dataset as [Book]Sheet!Short Name.
 [Book]Sheet!Long Name
 Show the name of the fitted dataset as [Book]Sheet!Long Name.
 Long Name only
 Only show the long name of the fitted dataset.
 Plot Legend
 Show as the Legend of the plot.

Add Legend Symbols

Specify whether to add legend symbols to the Label Box.

Equation

Show the fitting function equation, with parameter name or substitute parameter names by fitted values.

Parameter Table

Specify fitted parameters to be output.
 None
 Do not output the fitted parameters
 All Parameters
 Output all of the parameters
 Use ROI Box Tab Settings
 Output the parameters that selected under ROI Box tab.

Show Error in Parameter Table

Specify whether to show the parameters' standard errors.

Reduced ChiSqr

Specify whether to show the Reduced ChiSquare value.

RSquare

Specify whether to show the RSquare value.

Pearson's r

Specify whether to show Pearson's r (correlation coefficient) value.

Report tab
Besides the result text box pasted on the source graph, you can also output the fitted report to other destinations. Detailed settings can be specified in this tab.
Output To

Specify output report destination.

Significant Digits

Specify the significant digits. The default option System means using the significant digits setting in the Options dialog.

Function

Specify whether to output the fitting function name.

Input

Specify whether to show the name of the input dataset in the report. Options include:
 None
 Do not show the name of the input dataset.
 [Book]Sheet!Short Name
 Show the name of the input dataset as [Book]Sheet!Short Name.
 [Book]Sheet!Long Name
 Show the name of the input dataset as [Book]Sheet!Long Name.
 Long Name only
 Show the long name of the input dataset.
 Plot Legend
 Show as the Legend does.

Add Range

Specify whether to show the range of the input dataset in the report. Options include:
 None
 Do not show the range.
 Indices
 Use the indices to show the range of the input dataset.
 X Values
 Use the X values to show the range of the input dataset.

Output

Specify whether to show the name of the fitted dataset in the report.
 None
 Do not show the name of the fitted dataset.
 [Book]Sheet!Short Name
 Show the name of the fitted dataset as [Book]Sheet!Short Name.
 [Book]Sheet!Long Name
 Show the name of the fitted dataset as [Book]Sheet!Long Name.
 Long Name only
 Show the long name of the fitted dataset.
 Plot Legend
 Show as in the Legend of the plot.

Equation

Specify whether to output the fitting function equation.
 None
 Do not output the fitting function equation
 Equation with Names
 Output the equation with parameter names
 Equation with Values
 Output the equation with the fitted values of parameters

Parameter Table

Specify whether to output the parameter table.
 None
 Do not output the fitted parameter table
 All Parameters
 Output all of the parameters
 Use ROI Box Tab Settings
 Output the parameters that selected in the ROI Box tab.

Show Error in Parameter Table

Specify whether to output the parameters' standard errors.

Reduced ChiSqr

Specify whether to output the Reduced ChiSquare value.

RSquare

Specify whether to output the RSquare value.

Pearson's r

Specify whether to output Pearson's r (correlation coefficient) value.

Fit Curve tab
Specify the fitted curve settings.
X Data Type

Specify how to generate the X values of the fitted curve.
 Same X as Source Data
 The X values of the fitted curve are the same as the input X values.
 Use Source Graph Scale Type
 The X values of the fitted curve are plotted on the source data scale type.
 Uniform Linear X
 The X values of the fitted curve are plotted on an equallyspaced linear scale.

Number of Points

Specify the number of fitted curve points.

Range

This control is available only when X Data Type is either Uniform Linear or Log. It specifies the range of the X values of the fitted curve. Select one of the following options:
 Use Input Data Range + Margin
 Use the X range of the input data and range margin specified in the Range Margin (%) text box below.
 Span to Full Axis Range
 Span the X values to the full axis range.
 Custom
 Enter the minimum X value and maximum X value in the Min and Max edit boxes below.

Range Margin(%)

This control is available only when Use Input Data Range + Margin is selected for Range. It specifies the range margin into which the fitted curves extend.

Output Fit Curve To

Specify the fitted curve data destination.

Settings on the ROI
After you select the appropriate function for quick fitting, a yellow (default option) rectangle (ROI) will be added to the graph as below.
There are two small buttons at the topright of the ROI. Click button to close the ROI and click to expand the following menu.
New Output

Output the fitting results of current curve. You can specify what to output in Label tab and Report tab.

New Output for All Curves(N)

Output the fitting results of all curves in current layer.

New Output for All Layers(L)

Output the fitting results of all curves in all layers of current graph.

Update Last Output

Update the Label Box and the Report output.

Go to Report Worksheet

Active the report worksheet if it was created.

Change Data

Change fitting data/plot.

Change Function

Change fitting function.

Expand to Full Plot Range

Expand the ROI to full plot range.

Fix ROI Position

Fix the ROI Position. This item is same as the Fix(Prevent moving by ROI) check box in the ROI Box tab.

Switch to NLFit/Polynomial Fit/Linear Fit...

Open the NLFit/Polynomial Fit/Linear Fit dialog. The ROI range and specified fitting function will be inherited to the NLFit/Polynomial Fit/Linear Fit dialog.

Find X/Y

Open the Quick Fit Find X/Y dialog, which can be used to calculate the X/Y values for given Y/X.

Save Theme

Save the quick fit settings as theme.

Load Theme

Load quick fit settings.

Preferences

Open the Quick Fit Preferences dialog and reset the quick fit settings.
Note that, you are not allowed to reset fitting function in this dialog. To change fitting function, you can go to the above Change Function menu. Once the fitting function is set to linear or polynomial, the Settings tab with Apparent Fit check box will be available in this dialog.

