*

: scale pi ;
: zoom pi 1000 * ;
: offset scale 2 / ;
: xsize x scale * mx offset ;
: ysize y scale * my offset ;
: circle xsize + - dup * ysize + - dup * + sqrt dup t zoom / * tan sin ;
circle + t circle * circle + 2 t * sin + 1.75 * t 8 * sin +

Based on: Electron/Positron Structure - Franklin Amador