Fourier interpolation. If x is a vector, then x is resampled with n points. The data in x is assumed to be equispaced. If x is an array, then operate along each column of the array separately. If dim is specified, then interpolate along the dimension dim.
interpft
assumes that the interpolated function is periodic, and so assumptions are made about the end points of the interpolation.See also: interp1
The following code
t = 0 : 0.3 : pi; dt = t(2)-t(1); n = length (t); k = 100; ti = t(1) + [0 : k-1]*dt*n/k; y = sin (4*t + 0.3) .* cos (3*t - 0.1); yp = sin (4*ti + 0.3) .* cos (3*ti - 0.1); plot (ti, yp, 'g', ti, interp1(t, y, ti, 'spline'), 'b', ... ti, interpft (y, k), 'c', t, y, 'r+'); legend ('sin(4t+0.3)cos(3t-0.1','spline','interpft','data');
Produces the following figure
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