Interpolation method (spline)

Hello,

I am learning about interpolation.

In this link https://www.mathworks.com/help/matlab/ref/interp1.html, I see that the code to do interpolation is as follows:

vq = interp1(x,v,xq,method) specifies an alternative interpolation method: 'linear', 'nearest', 'next', 'previous', 'pchip', 'cubic', 'v5cubic', 'makima', or 'spline'. The default method is 'linear'.

I am wonder what is the "spline" method means? Is it the same as cubic?

Thanks,

Answer 1

[Star Strider]

From the documentation:

'spline':

‘Spline interpolation using not-a-knot end conditions. The interpolated value at a query point is based on a cubic interpolation of the values at neighboring grid points in each respective dimension.’

It does not appear to be the same as 'cubic'. According to the documentation, 'cubic' is currently the same as 'pchip'.