Manual

232 Statistics 2Var app
To define your
own fit
1. P r e s s
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 a menu of fit types.
4. Select User Defined from the menu.
5. Select the corresponding
Fit
n
field.
6. Enter an expression and press
E
. The
independent variable must be X, and the expression
must not contain any unknown variables. Example:
. Note that in this app,
variables must be entered in uppercase.
Logistic Fits the data to a logistic curve:
where L is the saturation value
for growth. You can store a
positive real value in L, or—if
L=0—let L be computed
automatically.
Quadratic Fits the data to a quadratic
curve: y = ax
2
+bx+c. Needs at
least three points.
Cubic Fits the data to a cubic
polynomial:
Quartic Fits to a quartic polynomial,
Trigonometric Fits the data to a trigonometric
curve: .
Needs at least three points.
User Defined Define your own fit (see below).
Fit type Meaning (Continued)
y
L
1 ae
bx–
+
--------------------------
=
yax
3
b
2
xcxd+++=
yax
4
bx
3
cx
2
dx e++++=
ya bxc+sin d+=
1.5 xcos 0.3 xsin+