trig_interp, an Octave code which evaluates the trigonometric interpolant to a set of evenly spaced data.
Given data at 2N+1 equally spaced points x(i), which we may assume are samples of a function f(x), the trigonometric interpolant has the form
q(x) = a0 + sum ( 1 <= i <= N) a(i) cos(i*x)
+ sum ( 1 <= i <= N) b(i) sin(i*x)
The computer code and data files described and made available on this web page are distributed under the MIT license
trig_interp is available in a MATLAB version and an Octave version.
divdif, an Octave code which uses divided differences to interpolate data.
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interp, an Octave code which can be used for parameterizing and interpolating data;
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test_approx, an Octave code which defines a number of test problems for approximation and interpolation.
test_interp, an Octave code which defines a number of test problems for interpolation, provided as a set of (x,y) data.
test_interp_1d, an Octave code which defines test problems for interpolation of data y(x), depending on a 1D argument.
trig_interp_basis, an Octave code which evaluates the cardinal basis functions for trigonometric interpolation of equally spaced data.
vandermonde_interp_1d, an Octave code which finds a polynomial interpolant to data by setting up and solving a linear system involving the Vandermonde matrix.