Available since LÖVE 0.9.0  
 This function is not supported in earlier versions. 
Gets the amount of size variation (0 meaning no variation and 1 meaning full variation between start and end).
variation = ParticleSystem:getSizeVariation( )
Nothing.
number variation
    © 2006–2016 LÖVE Development Team
Licensed under the GNU Free Documentation License, Version 1.3.
    https://love2d.org/wiki/ParticleSystem:getSizeVariation