generates these SVG images: File:Window function and frequency response - Bartlett-Hann.svg File:Window function and frequency response - Blackman.svg File:Window
image is a derivative work of the following images: File:Hyperbolic_Secant.svg licensed with Cc-by-sa-3.0, GFDL 2008-06-10T22:09:37Z Geek3 520x220 (13725
https://commons.wikimedia.org/wiki/File:Helmholtz_coil,_B_magnitude_cross_section.svg, done by Morn. Source code has been modified into fully object-oriented matplotlib