It's fine to call it. The next version of SymPy will use an LRU cache that should limit the memory growth of the cache.
Aaron Meurer On Wed, Nov 5, 2014 at 7:10 AM, nanaya tachibana <[email protected]> wrote: > Hello, > Yestday I found an memory issue in my experiment program. > I used sympy to generate legendre polynomials in my program and finally I > found this part of code cause the problem that the memory which used by > sympy cache cannot be released. > I'm new to sympy. Is it a good manner to call clear_cache() manually?Or > is there any problem in my code? > Thanks. > > > def generate_legendre_polynomials(max_degree): > """ > Create a list of legendre polynomials from degree of zero to degree of > max_degree. > """ > x, n = symbols('x n') > legendre_polynomial_list = [1, x] > > def nth_order_legendre(nth): > """ > Create nth legendre polynomials iteratively > according to Bonnet’s recursion formula. > """ > if nth <= 1: > return legendre_polynomial_list[nth] > > for i in range(2, nth + 1): > g = legendre_polynomial_list[i - 1] > h = legendre_polynomial_list[i - 2] > p = 1/n * ((2 * n - 1) * x * g - (n - 1) * h) > legendre_polynomial_list.append(expand(p.subs(n, i - 1))) > > nth_order_legendre(max_degree) > return legendre_polynomial_list > > legendre_polynomial_list = generate_legendre_polynomials(100) # legendre > polynomial table > def generate_target_function(degree, legendre_polynomial_list=None): > """ > Generate a target function randomly > according to the target function formula. > """ > x = symbols('x') > if legendre_polynomial_list is None or len(legendre_polynomial_list) - > 1 < degree: > legendre_polynomials = generate_legendre_polynomials(degree) > else: > legendre_polynomials = legendre_polynomial_list[:degree + 1] > alphas = [np.random.standard_normal() for i in range(degree + 1)] > > f = np.dot(alphas, legendre_polynomials) # sum of a_i * L_i > Z = integrate(f**2, (x, -1, 1)) / 2 # integrate f**2 from -1 to 1 > f = f / sqrt(Z) # normalized f > return f > > # memory usege goes up after each iteration > for i in range(1000): > generate_target_function(20, legendre_polynomial_list) > > -- > 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. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/b28eb9af-df2f-42b9-8715-815f8cbc9df6%40googlegroups.com > <https://groups.google.com/d/msgid/sympy/b28eb9af-df2f-42b9-8715-815f8cbc9df6%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAKgW%3D6KASJp5tzJ3n0uPukbuydYZGWJv6pBau3HYtR_O20EfTQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
