Calculates the fit using all current settings. If verbose mode is enabled in the menu ( button), then verbose results are listed in the Main Messsage Pane. The messages pane can be opened or closed using the Window > Show Messages menu command.

Selects the number of coefficients. For example, selecting "1" results in a constant value being fit. Some coefficients of lower order are not fit if forced or excluded from the fit.

Activates Point Weighting mode. In this mode, click on a point to assign it a new weight. Disable the mode by clicking .

Activates Point Deleting mode. In this mode, click on a point to delete it from being fit. Disable the mode by clicking . See Using Point Deletion in the 1-D Fit.

This is a 2-part button: The left-side checkbox enables Coefficient Forcing mode when you want specific coefficient values set to a value and excluded from the fitting process. The right button opens the 1-D Fit Properties dialog and selects the Set Coefs page. To force a coefficient, its value must be specified and the left-side checkbox must be checked. See Using 1-D Fit Coefficient Forcing.

This is a 2-part button: The left-side checkbox enables Sigma Clipping to auto-reject deviant points from the fit. The right button opens the 1-D Fit Properties dialog and activates the Sigma Clipping page. To use sigma clipping, the clipping parameters must be set on the Properties page and the left-side checkbox must be checked. See Sigma Clipping in the 1-D Fit.

Opens the 1-D Fit Properties dialog.

Opens the 1-D Fit Menu containing optional commands. These commands are used for changing some fitting properties and other purposes.

Check this box to limit the fit to marked regions. Only points inside the regions are fit. The regions are marked in Region Marking mode, which is activated by clicking the button.

Activates Region Marking mode. In this mode, drag the mouse pointer to draw selection rectangles; only points inside the rectangles are fit when is checked. Disable marking mode by clicking . See Using Point Selection Regions.

Activates Region Deleting mode. In this mode, click inside each fitting region to delete it. Disable the mode by clicking .