prepareCurveData
Prepare data inputs for curve fitting
Description
[
transforms data, if necessary, for curve fitting with the XOut,YOut]
= prepareCurveData(XIn,YIn)fit function. The
prepareCurveData function transforms data as follows:
Return data as columns regardless of the input shapes. Error if the number of elements do not match. Warn if the number of elements match, but the sizes differ.
Convert complex to real (remove imaginary parts) and warn of this conversion.
Remove
NaNorInffrom data and warn of this removal.Convert nondouble to double and warn of this conversion.
Specify XIn as empty if you want to fit curves to
y data against the index. If XIn is
empty, then XOut is a vector of indices into
YOut. The fit function can use the
vector XOut for the x data when there is
only y data.
[
transforms data including weights (XOut,YOut,WOut]
= prepareCurveData(XIn,YIn,WIn)WIn) for curve fitting
with the fit function.
When you generate code from the Curve Fitting app, the generated code includes
a call to prepareCurveData (or prepareSurfaceData for surface
fits). You can call the generated file from the command line with your original
data or new data as input arguments, to recreate your fits and plots. If you
call the generated file with new data, the prepareCurveData
function ensures you can use any data that you can fit in the Curve Fitting app,
by reshaping if necessary to column doubles and removing
NaNs, Infs, or the imaginary parts of
complex numbers.
Examples
Reshape Rows to Columns for Curve Fitting
The following commands load the example titanium data in which x and y are row vectors. Attempting to use rows as inputs to the fit function produces an error. The prepareCurveData function reshapes x and y to columns for use with the fit function.
[x,y] = titanium(); [x,y] = prepareCurveData(x,y);
Create and plot a fit using the reshaped data.
f = fit(x,y,'smoothingspline');
plot(f,x,y)