----------------- help for grols -----------------Graphing OLS Regression -----------------------

To invoke, type

. grols

This program shows the regression line between X and Y using Ordinary Least Squares (OLS) Regression.

When you run grols a simple regression line is displayed and with a single point which is the predicted value for Y when X is 0. You can change the intercept (a) and slope (b) of the line, and you can increase/decrease X to show how the predicted value of Y changes as X changes, as described below.

The dialog box allows you to adjust a-.1 and a+.1 : adding and subtracting .1 from the intercept. b-.1 and b+.1 : adding and subtracting .1 from the slope. X-1 and X+1 (if you choose "show point at prected value of X") This allows you to add and subtract 1 from X, and see how it impacts the predicted value of Y.

The "Done" button quits the program. The "Reset" button resets a, b and X to their default values, i.e. a=0, b=1, and X=0. The "Help" button brings up this help screen.

If you have comments or suggestions, please email Michael Mitchell at mnmatucla.edu .

Author ------

Michael N. Mitchell Statistical Computing and Consulting UCLA, Academic Technology Services mnmatucla.edu