- #1
Cristiano
- 33
- 0
Suppose that a parameter y= 123.
That parameter is somehow "perturbed" and its instantaneous value is:
y(t)= 123 +
sin(t - 50°) * 9 +
sin(t * 3 + 10°) * 3 +
sin(t * 20 + 60°) * 4
Suppose that I don't know the above formula, but I can calculate y(t) for any t. Hence I decide to use the Fourier transform to infer all the y's components.
If I use a sufficient number of samples to calculate y(t) (I currently use 216 samples) for 0 ≤ t ≤ 2π, I obtain:
y(t)= 122.999955606783 +
sin(t - 49.9942506502916°) * 8.99994072213981 +
sin(t * 3 + 10.0193463603278°) * 2.9999458244411 +
sin(t * 20 + 60.11052441823°) * 4.00000160503959
which is a very good result, while if I try to calculate y(t) for arbitrary t, I obtain a totally meaningless result.
Please, could somebody help me?
Thank you
That parameter is somehow "perturbed" and its instantaneous value is:
y(t)= 123 +
sin(t - 50°) * 9 +
sin(t * 3 + 10°) * 3 +
sin(t * 20 + 60°) * 4
Suppose that I don't know the above formula, but I can calculate y(t) for any t. Hence I decide to use the Fourier transform to infer all the y's components.
If I use a sufficient number of samples to calculate y(t) (I currently use 216 samples) for 0 ≤ t ≤ 2π, I obtain:
y(t)= 122.999955606783 +
sin(t - 49.9942506502916°) * 8.99994072213981 +
sin(t * 3 + 10.0193463603278°) * 2.9999458244411 +
sin(t * 20 + 60.11052441823°) * 4.00000160503959
which is a very good result, while if I try to calculate y(t) for arbitrary t, I obtain a totally meaningless result.
Please, could somebody help me?
Thank you