It is because the integral can not be solved symbolically by sympy so it has to be evaluated numerically _for each point t that is plotted_.
first plot: evaluate the integral symbolically (slow), calculate the value of the result at each t (fast as it is only arithmetics) last plot: try to evaluate the integral symbolically (slow and useless as it fails), fallback to numeric integrations at each t (slow because numeric integration needs a lot of sampling) On 29 July 2013 08:45, <[email protected]> wrote: > Ok, i see this isn't implemented yet. But could you give me a hint why >> while the last plot the kernel is busy all the time ? >> > > > import sympy > from sympy.plotting import plot > from sympy.abc import t,tau > > u_t = 2 * DiracDelta(t) > g_t = 0.5 * ( Heaviside(t)-Heaviside(t-2) ) > > plot( integrate( u_t.subs(t,tau)*g_t.subs(t,t-tau), (tau,-10, 10)), > (t,-10,10)) > plot( integrate( u_t.subs(t,tau)*u_t.subs(t,t-tau), (tau,-10, 10)), > (t,-10,10)) > plot( integrate( g_t.subs(t,tau)*g_t.subs(t,t-tau), (tau,-10, 10)), > (t,-10,10)) > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sympy. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. For more options, visit https://groups.google.com/groups/opt_out.
