Briefly |
With an active graph that allows function plotting (scatter plot, histogram, function plot, and others), choose Plot Function from the Graph menu. Enter the formula - just the right-hand-side - of the function you want to plot. |
Any graph that has two numeric axes will allow you to plot a function.
Be sure the graph is active (there is a graph menu present). Then you can choose Plot Function from the Graph menu. (You can also choose Plot Function from the graph's contextual menu.)
The formula editor appears.
Enter the formula you want but only the right-hand side. You can use any symbol (e.g., x) for the independent variable, but it's often prudent to use the genuine variable name (here, time)--in case you need that formula again somewhere else.
To see the function, click Apply or press . Here's an example of a function plotted on a scatter plot of some temperature data from the South Pole. Brrr.
To close the formula editor window and continue working, click OK.
More about functions
To edit a function, double-click the formula (the text below the graph, not the curve).
To get rid of a function, edit an existing function (double-click the formula at the bottom) and erase the formula in the formula editor. When you close the editor, the function goes away. Another way to get rid of the function is to choose Clear Formula from the contextual menu for the function.
To add a new function, choose Plot Function again from the Graph menu. It will appear in a different color.
Once you have a function, you can plot residuals.
See also: Adding lines to scatter plots.
Other uses of formulas:
Writing formulas for attributes
Writing formulas for statistics