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You can generate and use MATLAB^{®} code from an interactive
session in the Curve Fitting app. In this way, you can transform your
interactive analysis into reusable functions for batch processing
of multiple data sets. You can use the generated file without modification,
or you can edit and customize the file as needed.

To generate code for all fits and plots in your Curve Fitting app session follow these steps:

Select

**File**>**Generate Code**.The Curve Fitting app generates code from your session and displays the file in the MATLAB Editor. The file includes all fits and plots in your current session. The file captures the following information:

Names of fits and their variables

Fit settings and options

Plots

Curve and surface fitting objects and methods used to create the fits:

A cell-array of

`cfit`or`sfit`objects representing the fitsA structure array with goodness-of fit information.

Save the file.

To recreate your fits and plots, call the file from the command line with your original data as input arguments. You also can call the file with new data.

For example, enter:

[fitresult, gof] =(a, b, c)myFileName

where `a`, `b`,
and `c` are your variable names, and * myFileName* is
the file name.

Calling the file from the command line does *not* recreate
your Curve Fitting app and session. When you call the file, you get
the same plots you had in your Curve Fitting app session in standard MATLAB figure
windows. There is one window for each fit. For example, if your fit
in the Curve Fitting app session displayed main, residual and contour
plots, all three plots appear in a single figure window.

The curve and surface fit objects (`cfit` and ` sfit`)
store the results from a fitting operation, making it easy to plot
and analyze fits at the command line.

`cfit` and `sfit` objects
are a subclass of `fittype` objects, so they inherit
all the same methods of `fittype` and provide additional
methods. To learn about available methods, see `cfit`, `sfit` and `fittype`.

To export a fit to the MATLAB workspace, follow these steps:

Select a fit and save it to the MATLAB workspace using one of these methods:

Right-click the fit listed in the Table of Fits and select

**Save Fit**to Workspace`myfitname`Select a fit figure in the Curve Fitting app and select

**Fit**>**Save to Workspace**.

The Save Fit to MATLAB Workspace dialog box opens.

Edit the names as appropriate. If you previously exported fits, the toolbox automatically adds a numbered suffix to the default names so there is no danger of overwriting them.

Choose which options you want to export by selecting the check boxes. Check box options are as follows:

**Save fit to MATLAB object named**— This option creates a`fittedmodel``cfit`or`sfit`object, that encapsulates the result of fitting a curve or surface to data. You can examine the fit coefficients at the command line, for example:fittedmodel Linear model Poly22: fittedmodel1(x,y) = p00 + p10*x + p01*y + p20*x^2... + p11*x*y + p02*y^2 Coefficients (with 95% confidence bounds): p00 = 302.1 (247.3, 356.8) p10 = -1395 (-1751, -1039) p01 = 0.03525 (0.01899, 0.05151) p20 = 1696 (1099, 2293) p11 = -0.1119 (-0.1624, -0.06134) p02 = 2.36e-006 (-8.72e-007, 5.593e-006)

You also can treat the

`cfit`or`sfit`object as a function to make predictions or evaluate the fit at values of X (or X and Y). See the`cfit`and`sfit`reference page.**Save goodness of fit to MATLAB struct named**— This option creates a structure array that contains statistical information about the fit, for example:`goodness`goodness = sse: 0.0234 rsquare: 0.9369 dfe: 128 adjrsquare: 0.9345 rmse: 0.0135

**Save fit output to MATLAB struct named**— This option creates a structure array that contains information such as numbers of observations and parameters, residuals, and so on. For example:`output`output = numobs: 134 numparam: 6 residuals: [134x1 double] Jacobian: [134x6 double] exitflag: 1 algorithm: 'QR factorization and solve' iterations: 1

**Note:****Goodness of fit**and**Output**arrays are outputs of the`fit`function. See the`fit`reference page.

Click

**OK**to save the fit options to the workspace.

After you save your fit to the workspace, you can use fit postprocessing functions. For an example, see Analyzing Your Best Fit in the Workspace. For more information and a list of functions, see Fit Postprocessing.

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