20060301
Drawing a Logarithmic Regre
ss
ion Graph
Logarithmic regression expresses
y
as a logarithmic function of
x
. The normal logarithmic
regression formula is
y
=
a
+
b
· ln(
x
). If we say that X = ln(
x
), then this formula corresponds
to the linear regression formula
y
=
a
+
b
·X.
S
Cla
ss
Pad Operation
Start the graphing operation from the Statistics application’s Graph window or List window.
From the Graph window
Tap [Calc] [Logarithmic Reg] [OK] [OK]
.
From the Li
s
t window
Tap [SetGraph][Setting...], or
'
.
On the Set StatGraphs dialog box that appears, configure a StatGraph setup with the
setting shown below, and then tap [Set].
Type:
LogR
Tap
x
to draw the graph.
7-5-9
Graphing Paired-Variable Statistical Data
The following is the logarithmic regression model formula.
y
=
a
+
b
·ln(
x
)
a
:
regression constant term
b
: regression
coefficient
r
: correlation
coefficient
r
2
:
coefficient of determination
MSe
: mean square error
• MSe
=
1
n
–
2
i
=1
n
(
y
i
– (
a
+
b·
ln
(
x
i
)))
2
Summary of Contents for ClassPad 330
Page 11: ...20060301 20090601 ClassPad 330 ClassPad OS Version 3 04 ...
Page 277: ...20060301 3 3 10 Storing Functions 3 Tap AND Plot OR Plot ...
Page 779: ...20090601 S Graph Line Clustered C S Graph Line Stacked E 13 9 2 Graphing ...
Page 780: ...20090601 S Graph Line 100 Stacked F S Graph Column Clustered G 13 9 3 Graphing ...
Page 781: ...20090601 S Graph Column Stacked I S Graph Column 100 Stacked J 13 9 4 Graphing ...
Page 782: ...20090601 S Graph Bar Clustered K S Graph Bar Stacked 9 13 9 5 Graphing ...