| 1 | | Sorry forgot the brackets.... |
| 2 | | |
| 3 | | |
| 4 | | {{{ |
| 5 | | def _evalf_(self, f, x, a, b, parent = None): |
| 6 | | """ |
| 7 | | Returns numerical approximation of the integral |
| 8 | | |
| 9 | | EXAMPLES:: |
| 10 | | |
| 11 | | sage: from sage.symbolic.integration.integral import definite_integral |
| 12 | | sage: h = definite_integral(sin(x)/x^2, x, 1, 2); h |
| 13 | | integrate(sin(x)/x^2, x, 1, 2) |
| 14 | | sage: h.n() # indirect doctest |
| 15 | | 0.4723991772689525... |
| 16 | | |
| 17 | | TESTS: |
| 18 | | |
| 19 | | Check if #3863 is fixed:: |
| 20 | | |
| 21 | | sage: integrate(x^2.7 * e^(-2.4*x), x, 0, 3).n() |
| 22 | | 0.154572952320790 |
| 23 | | |
| 24 | | #Check if #8321 is fixed: |
| 25 | | |
| 26 | | sage: d = definite_integral(sin(x)/x^2, x, 1, 2) |
| 27 | | sage: d.n(77) |
| 28 | | 0.4723991772689525199904 |
| 29 | | """ |
| 30 | | #from sage.gsl.integration import numerical_integral |
| 31 | | # The gsl routine returns a tuple, which also contains the error. |
| 32 | | # We only return the result. |
| 33 | | #return numerical_integral(f, a, b)[0] |
| 34 | | |
| 35 | | #Lets try mpmath instead: |
| 36 | | |
| 37 | | import sage.libs.mpmath.all as mpmath |
| 38 | | |
| 39 | | try: |
| 40 | | precision = parent.prec() |
| 41 | | mpmath.mp.prec = precision |
| 42 | | except AttributeError: |
| 43 | | precision = mpmath.mp.prec |
| 44 | | |
| 45 | | mp_f = lambda z: \ |
| 46 | | f(x = mpmath.mpmath_to_sage(z,precision)) |
| 47 | | |
| 48 | | return mpmath.call(mpmath.quad,mp_f,[a,b]) |
| 49 | | }}} |
| 50 | | |
| 51 | | Tests: |
| 52 | | |
| 53 | | |
| 54 | | {{{ |
| 55 | | sage: sage: sage: from sage.symbolic.integration.integral import definite_integral |
| 56 | | sage: sage: h = definite_integral(sin(x)/x^2, x, 1, 2); h |
| 57 | | integrate(sin(x)/x^2, x, 1, 2) |
| 58 | | sage: h.n() |
| 59 | | 0.472399177268953 |
| 60 | | sage: h.n(77) |
| 61 | | 0.4723991772689525199904 |
| 62 | | sage: h.n(100) |
| 63 | | 0.47239917726895251999041133798 |
| 64 | | }}} |
