Editing Pink noise (section)

== Generation ==
[[File:White to pink filter.png|thumb|500px|The spatial filter which is convolved with a one-dimensional white noise signal to create a pink noise signal<ref name="Das-thesis"/>]]
Pink noise can be computer-generated by first generating a white noise signal, Fourier-transforming it, then dividing the amplitudes of the different frequency components by the square root of the frequency (in one dimension), or by the frequency (in two dimensions) etc. <ref name="Das-thesis"/> This is equivalent to spatially filtering (convolving) the white noise signal with a white-to-pink-filter. For a length <math>N</math> signal in one dimension, the filter has the following form:<ref name="Das-thesis"/>

<math display="block">a(x)=\frac{1}{N} \left[ 1+ \frac{1}{\sqrt{N/2}} \cos \pi (x-1) + 2 \sum_{k=1}^{N/2-1} \frac{1}{\sqrt{k}} \cos {\frac{2\pi k}{N}(x-1)} \right].</math>

Matlab programs are available to generate pink and other power-law coloured noise in [http://www.maxlittle.net/software/ one] or  [https://www.mathworks.com/matlabcentral/fileexchange/121108-coloured-noise any number] of dimensions.