Nonlinear Curve Fitting
Data Linearization Method for
Exponential Curve Fitting.
Fit the curve to
the data points .
Taking the logarithm of both sides we obtain , thus
.
Introduce the change of variable . Then
the previous equation becomes
which is a linear equation in the variables X and Y.
Use the change of variables on
all the data points and obtain
for .
Fit the points
with
a "least squares line" of the form .
Comparing the equations we
see that . Thus
are used to construct the coefficients which are then used to "fit the curve"
to the given data points in
the xy-plane.
Data Linearization Method for a
Power Function Curve Fitting.
Fit the curve to
the data points .
Taking the logarithm of both sides we obtain , thus
.
Introduce the change of variable . Then
the previous equation becomes
which is a linear equation in the variables X and Y.
Use the change of variables on
all the data points and obtain
for .
Fit the points
with
a "least squares line" of the form .
Comparing the equations we
see that . Thus
are used to construct the coefficients which are then used to "fit the curve"
to the given data points in
the xy-plane.
|