Plots illustrating the cause of red-noise leak in Fourier analysis. The top left-side plot shows a sine wave with two full periods resulting in no red-noise leak, depicted by the continuous sine wave transfer from blue to orange. The right-side plot shows a non-integer multiple of the period resulting in a discontinuity in the Fourier transform. The middle row shows sine waves with periods T = 1/(15 Hz), with the left-side plot having again full integer periods and the right-side plot conversely having a discontinuity. The bottom row shows the respective periodograms.