Cubic spline data interpolation
You also can perform spline interpolation using the interp1
function with the command interp1(x,y,xq,'spline')
.
While spline
performs interpolation on rows of
an input matrix, interp1
performs interpolation
on columns of an input matrix.
A tridiagonal linear system (possibly with several right-hand
sides) is solved for the information needed to describe the coefficients
of the various cubic polynomials that make up the interpolating spline. spline
uses
the functions ppval
, mkpp
,
and unmkpp
. These routines form a small suite
of functions for working with piecewise polynomials. For access to
more advanced features, see interp1
or
the Curve Fitting Toolbox™ spline functions.
[1] de Boor, Carl. A Practical Guide to Splines. Springer-Verlag, New York: 1978.