Dear all, First of all, many thanks for Sympy, which is a great tools !
I try to integrate a product of two sinus functions such as : f(x) = sin(pi*n/L*x) * sin(pi*m/L*x) where n and m are two positive integer (and L>0). I've found the correct expected values (L/2 if m=n, 0 otherwise). But if I make a small change of variable, moving x to x+L/2, then Sympy fails to provide me an answer. Is there a way to "help" Sympy finding the correct solution ? An example is below : ---- z = symbols('z') m, n = symbols('m n', positive=True, integer=True) L = symbols('L', positive=True, real=True) def e1(z, n, L): k_n = n*pi/L return sin(k_n*(z)) def e2(z, n, L): k_n = n*pi/L return sin(k_n*(z+L/2)) Imn1 = integrate(fu(e1(z, n, L)*e1(z, m, L)), (z, 0, L)) Imn2 = integrate(fu(e2(z, n, L)*e2(z, m, L)), (z, -L/2, L/2)) --- In [16]: Imn1 Out[16]: Piecewise((L/2, m == n), (0, True)) In [17]: Imn2 Out[17]: Integral(sin(pi*m*(L/2 + z)/L)*sin(pi*n*(L/2 + z)/L), (z, -L/2, L/2)) Best regards, Julien -- 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 sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/adbc610b-360a-438b-ba46-1446ae059c5c%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.