User`s guide

3 Fitting Data
3-62
To create a first-degree polynomial equation with zero offset, you must create
a custom linear equation. As described in “Example: Fitting with Custom
Equations” on page 3-46, you can create a custom equation using the Fitting
GUI by selecting
Custom Equations from the Type of fit list, and then clicking
the
New Equation button.
The Linear Equations pane of the Create Custom Equation GUI is shown
below.
Before fitting, you should exclude the data point associated with the absentee
ballots from each data set because these voters did not use the butterfly ballot.
As described in “Marking Outliers” on page 2-27, you can exclude individual
data points from a fit either graphically or numerically using the Exclude GUI.
For this example, you should exclude the data numerically. The index of the
absentee ballot data is given by
ind = find(strcmp(counties,'Absentee Ballots'))
ind =
68
Create a first-degree
polynomial with zero offset.
Assign a meaningful name
to the equation.
Clear this check box.