POLYFIT

Returns the coefficients of a polynomial fitted to the supplied function data.

Format

POLYFIT (x, y, order)

Arguments

 
x
The array of x values.
y
The array of y values.
order
The maximum order of the polynomial, the returned coefficients are from 0th order to this value.

Examples

The following commands:
var cre var=xx rea=(series2(0, 20, 20))  
var cre var=yy rea=(1.0 + 1.2*xx + 2.5*xx**2 + 2.0*xx**3)  
var cre var=pp rea=(polyfit(xx, yy, 5))
produce the array result.
The coefficients are ordered from the 0th order to the nth order from left to right.
[1.0, 1.2, 2.5, 2.0, 0.0, 0.0]