Katex is available here, so you can write
$$$\hat{f}(f) = \int_\infty^{-\infty} e^{2\pi ft}sample(t)dt$$$
...but it looks like continuous FT.
For FFT/DFT sum is just enough.
Katex is available here, so you can write
$$$\hat{f}(f) = \int_\infty^{-\infty} e^{2\pi ft}sample(t)dt$$$
...but it looks like continuous FT.
For FFT/DFT sum is just enough.