Purpose: The purpose of this program is to show the effect of a
change in the slope, the constant (i.e., the intercept) or a point (x) on the
regression line. The equation resulting equation is also displayed.Download: You can download this program from within Stata by
typing search grolsw (see
How can I use the search command to search for programs and get additional
help? for more information about using search).
Use of program: To use this program, type grolsw in the Stata command window.
Nine buttons govern the use of the program. One can be added or subtracted
from either a (the intercept) or x (the point), and .1 can be added or
subtracted from b (the slope). Pressing the "done" button will
exit the user from the program (but not from Stata). The red box indicates
the point that can be moved (x).Examples: The following shows the first screen of the grolsw
program. From here, any of the nine buttons can be pressed.
The following shows the results of pressing the "b – .1" button
five times. Notice that the slope is steeper and that the changes are
indicated in the equations at the top of command box.
The following shows the results of pressing the "a + 1" button five
times. Notice that the intercept has moved up on the
y axis five units.
The following shows the results of pressing the "x + 1" button
once. Notice that the moving point, displayed as the red box,
has moved to the right one unit. Also notice that the predicted value
increased by 1.5 because the slope is 1.5.
