Least square curve fit with out differentiation(Gra​mdeterminant method)

Curdat.m is a data file. You can change to get your
need.
Polycurve.m is polynomial basis file.
Graf.m is the user’s basis file. You can change to
match your choice.
Curfit.m Gives the polynomial curve and the graph.
Gramplot.m gives the curve for selected basis.

Example ;
Gramplot() gives the result. Deviations and
locations are included.
Curfit(4) gives the result.

Least square curve fit is the principle. In the formulation,
differentiation is avoided. Instead,an inner-product is
designed and Gram-matrix is created. The curve F is

F = ∑ ai fi ; i = 1..n

ai are the parameters
fi are the basis functions