home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Turnbull China Bikeride
/
Turnbull China Bikeride - Disc 1.iso
/
ARGONET
/
PD
/
MATHS
/
RLAB
/
RLAB125.ZIP
/
!RLaB
/
toolbox
/
polyfit
< prev
next >
Wrap
Text File
|
1996-04-09
|
809b
|
36 lines
//-------------------------------------------------------------------//
// Syntax: polyfit(x, y, n)
// Description:
// Polynomial curve fitting
//
// polyfit(x,y,n) finds the coefficients of a polynomial
// formed from the data in vector x of degree n that fits
// the data in vector y in a least-squares sense.
//
// polyfit returns the coefficients of the n-th order polynomial
// (in decending powers of x).
//
// See Also: poly, polyval, roots
//
//-------------------------------------------------------------------//
polyfit = function(x, y, n)
{
local(x)
x = x[:];
m = x.nr;
if (m != y.nr) {
error("row dim. of 1st argument must match row dim. of 2nd argument");
}
a[;n+1] = ones(m,1);
for (i in n:1:-1) {
a[;i] = a[;i+1].*x;
}
return a\y;
};