|$data||This is your data you are trying to fit. Size=n|
2D array. size (n, noCoefs). Row 0 is the evaluation
of function x0 at all the points in y. Row 1 is the evaluation of
of function x1 at all the points in y, ... etc.
Example of $functions array Structure:
$data is a set of 10 points that we are trying to model using the linear combination of 3 functions.
$yfit = linfit1d $data, $funcs
1D Fit linear combination of supplied functions to data using min chi^2 (least squares).
Usage: ($yfit, [$coeffs]) = linfit1d [$xdata], $data, $fitFuncs, [Options...]
Signature: (xdata(n); ydata(n); $fitFuncs(n,order); [o]yfit(n); [o]coeffs(order))
Uses a standard matrix inversion method to do a least squares/min chi^2 fit to data.
Returns the fitted data and optionally the coefficients.
One can thread over extra dimensions to do multiple fits (except the order can not be threaded over - i.e. it must be one fixed set of fit functions fitFuncs.
The data is normalised internally to avoid overflows (using the mean of the abs value) which are common in large polynomial series but the returned fit, coeffs are in unnormalised units.
# Generate data from a set of functions $xvalues = sequence(100); $data = 3*$xvalues + 2*cos($xvalues) + 3*sin($xvalues*2); # Make the fit Functions $fitFuncs = cat $xvalues, cos($xvalues), sin($xvalues*2); # Now fit the data, Coefs should be the coefs in the linear combination # above: 3,2,3 ($yfit, $coeffs) = linfit1d $data,$fitFuncs;
Options: Weights Weights to use in fit, e.g. 1/$sigma**2 (default=1)
|perl v5.20.3||LINFIT (3)||2015-08-12|