/span><span class='hljl-t'>
</span><span class='hljl-n'>nsteps</span><span class='hljl-t'> </span><span class='hljl-oB'>=</span><span class='hljl-t'> </span><span class='hljl-ni'>400</span><span class='hljl-t'>
</span><span class='hljl-n'>tmax</span><span class='hljl-t'> </span><span class='hljl-oB'>=</span><span class='hljl-t'> </span><span class='hljl-n'>nsteps</span><span class='hljl-oB'>*</span><span class='hljl-n'>δt</span><span class='hljl-t'>
</span><span class='hljl-n'>tspan</span><span class='hljl