beautypg.com

Defining a regression model, Choose a fit, Fit types – HP Prime Graphing Calculator User Manual

Page 233

background image

Statistics 2Var app

229

Defining a regression model

You define a regression model in Symbolic view. There are
three ways to do so:

Accept the default option to fit the data to a straight
line.

Choose a pre-defined fit type (logarithmic,
exponential, and so on).

Enter your own mathematical expression. The
expression will be plotted so that you can see how
closely it fits the data points.

Choose a fit

1. Press

Y

to display the Symbolic view.

2. For the analysis you are interested in (S1 through S5),

select the

Type

field.

3. Tap the field again to see the menu of fit types.
4. Select your preferred fit type from the menu. (See “Fit

types” on page 229.)

Fit types

Twelve fit types are available:

Fit type

Meaning

Linear

(Default.) Fits the data to a

straight line: y = mx+b. Uses a

least-squares fit.

Logarithmic

Fits the data to a logarithmic

curve: y = m lnx + b.

Exponential

Fits the data to the natural

exponential curve:

.

Power

Fits the data to a power curve:

.

.

Exponent

Fits the data to an exponential

curve: .

Inverse

Fits the data to an inverse

variation:

y

b e

mx

=

y

b x

m

=

y

b m

x

=

y

m

x

---- b

+

=