To define your own fit

Fit model

Meaning (Continued)

 

 

Quadratic

Fits to a quadratic curve,

 

y = ax2+bx+c. Needs at least

 

three points.

Cubic

Fits to a cubic curve,

 

y = ax3+bx2+cx+d. Needs at least

 

four points.

Logistic

Fits to a logistic curve,

 

L

 

y = -------------------------- ,

 

1 + ae(–bx)

 

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.

Exponent

Fits to an exponent curve,

 

y = abx .

Trigonometric Fits to a trigonometric curve,

y= a ⋅ sin(bx + c) + d . Needs at least three points.

User Defined Define your own expression (in Symbolic view.)

1.In Numeric view, make sure is set.

2.Display the Symbolic view.

3.Highlight the Fit expression (Fit1, etc.) for the desired data set.

4.Type in an expression and press .

The independent variable must be X, and the

expression must not contain any unknown variables. Example:1.5 ⋅ cosx + 0.3 ⋅ sinx .

This automatically changes the Fit type (S1FIT, etc.) in the Symbolic Setup view to User Defined.

Statistics aplet

10-13