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.

User

Define your own expression (in

Defined

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 ⋅ cos x + 0.3 ⋅ sinx .

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

Computed statistics

One-variable

 

Statistic

Definition

 

 

 

 

NΣ

Number of data points.

 

TOTΣ

Sum of data values (with their

 

 

frequencies).

 

 

 

 

 

 

Statistics aplet

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