We have added a Fitting Equation checkbox and Custom Fitting Equation editbox to the plot_matrix dialog. Note that this is only enabled when Linear Fit is active in Options branch.

In previous versions, if the fitted curve was shown in the Graph Maker, the equation would be shown in a reference line label. If linear fit curve was selected in the Mini-Toolbar, the reference line label of this curve was set to fitting equation y = $(a0,-)$(a1,-+)*x as in the graph maker. If the label was shown for such a line, the equation would show.