User's Manual

Statistics 12-23
8312STAT.DOC TI-83 international English Bob Fedorisko Revised: 02/19/01 12:42 PM Printed: 02/19/01 1:37
PM Page 23 of 38
When you execute some regression models, the TI
-
83
computes and stores diagnostics values for
r (correlation
coefficient) and
r
2
(coefficient of determination) or for R
2
(coefficient of determination).
r and r
2
are computed and stored for these regression
models.
LinReg(ax+b) LnReg PwrReg
LinReg(a+bx) ExpReg
R
2
is computed and stored for these regression models.
QuadReg CubicReg QuartReg
The r and r
2
that are computed for LnReg, ExpReg, and
PwrReg are based on the linearly transformed data. For
example, for
ExpReg (y=ab^x), r and r
2
are computed on
ln y=ln a+x(ln b).
By default, these values are not displayed with the results
of a regression model when you execute it. However, you
can set the diagnostics display mode by executing the
DiagnosticOn or DiagnosticOff instruction. Each instruction
is in the
CATALOG
(Chapter 15).
Note:
To set
DiagnosticOn
or
DiagnosticOff
from the home
screen, press
y
[
CATALOG
], and then select the instruction for the
mode you want. The instruction is pasted to the home screen. Press
Í
to set the mode.
When DiagnosticOn is set, diagnostics are displayed with
the results when you execute a regression model.
When DiagnosticOff is set, diagnostics are not displayed
with the results when you execute a regression model.
Diagnostics
Display Mode