FFT, Fast-Fourier-Transform
Experiments with perturbation/reconstruction

Please specify the input length of your trigonometric sum:
M= Important: 1 <= M <= 7 !

Please specify the number n+1 of evaluation points:
Observe: n+1 must have a prime factorization n+1 = (2**k)(3**i)(5**j).
n+1= Important: 2m+1 <= n+1 <= 2000 !

Specify the coefficients of your trigonometric sum here as a₀,a₁,b₁,a₂,b₂,...a_m,b_m,
entries separated by blank or comma.
Example: 0,2,2   for the case y = 0 + 2*cos(1*x) + 2*sin(1*x)
0 2 2

specify in percent the error level for the artificial generated errors
error level=

and in the following box the droplevel, again in percent, relative to the largest coefficient.
That implies that all coefficients in the trigonometric interpolation of the perturbed data with an absolute value below max*drop/100 will set equal to zero. Here max is the maximum absolute value of the original input coefficients.
drop=

Click on "evaluate", in order to submit your input.