Happy New Year to everybody!

This math firework has been done with

>function plotfirework () ...
$fullwindow(); setplot(-1,1,-1.5,0.5); clg;
$barcolor(rgb(0.2,0.2,0.2)); barstyle("#"); plotbar(-2,-2,4,4);
$n=200; phi=random(1,n)*2pi;
$t=0:0.01:1;
$loop 1 to n;
$   c=random(3,1); c=rgb(c[1],c[2],c[3]);
$   d=0.9+random()*0.1;
$   plot2d(d*t*cos(phi[#]),d*t*sin(phi[#])-t^2/2, ..
$      style="-",color=c,>add);
$end;
$reset();
$endfunction
>plotfirework: