HI there,
straightforward one, in Sage v9.0 on Ubuntu Linux the following code:
g(x)=gamma_inc(2,11/5)*x
numerical_integral(g,2,5)
results in the following error:
---------------------------------------------------------------------------
SystemError Traceback (most recent call last)
/usr/lib/python3/dist-packages/sage/all_cmdline.py in <module>
1 __tmp__=var("x"); g = symbolic_expression(gamma_inc(Integer(2),Integer(11)/Integer(5))*x).function(x)
2 show(g)
----> 3 numerical_integral(g,Integer(2),Integer(5))
/usr/lib/python3/dist-packages/sage/calculus/integration.pyx in sage.calculus.integration.numerical_integral (build/cythonized/sage/calculus/integration.c:4042)()
353 _b = b
354 W = <gsl_integration_workspace*> gsl_integration_workspace_alloc(n)
--> 355 sig_on()
356 gsl_integration_qag(&F,_a,_b,eps_abs,eps_rel,n,rule,W,&result,&abs_err)
357 sig_off()
SystemError: calling remove_from_pari_stack() inside sig_on()
This integral does work fine if gamma_inc is replaced by a constant involving the gamma function, and n(gamma_inc(2,11/5)) works fine as well. A bug?
