我目前正在使用Sympy来帮助我进行数学计算.现在,我正在尝试执行数值集成,但是在我运行脚本的任何时候都会出现错误.这是脚本：

from sympy import *
cst = { 'qe':1.60217646*10**-19, 'm0':N(1.25663706*10**-6) }

d = 3.6*10**-2
l = 20.3*10**-2
n = 217.0
I = 10.2

# Circum of loops
circ = l/n;
# Radius
r = N( circ/(2*pi) )
# Flux through a ring a distance R from the ceter
def flux(rad, I, loopRad):
    distFromWire = loopRad - rad
    bPoint = cst['m0']*I/(2*pi*distFromWire)
    return ( bPoint*2*pi*rad )

# Integrate from r=0 to r=wireRad
x = Symbol('x')
ig = Symbol('ig')
ig = flux(x, I, r)
print(ig)
integrate(ig*x,x)

我确信实际的物理/数学可能有问题,但是现在我只想要它进行整合.这是我运行脚本时得到的输出：

8.05359718208634e-5*x/(-6.28318530717959*x + 0.000935483870967742)
Traceback (most recent call last):
  File "script.py", line 34, in <module>
    integrate(ig*x,x)
  File "C:\Python27\lib\site-packages\sympy\utilities\decorator.py", line 24, in threaded_func
    return func(expr, *args, **kwargs)
  File "C:\Python27\lib\site-packages\sympy\integrals\integrals.py", line 847, in integrate
    return integral.doit(deep = False)
  File "C:\Python27\lib\site-packages\sympy\integrals\integrals.py", line 364, in doit
    antideriv = self._eval_integral(function, xab[0])
  File "C:\Python27\lib\site-packages\sympy\integrals\integrals.py", line 577, in _eval_integral
    parts.append(coeff * ratint(g, x))
  File "C:\Python27\lib\site-packages\sympy\integrals\rationaltools.py", line 42, in ratint
    g, h = ratint_ratpart(p, q, x)
  File "C:\Python27\lib\site-packages\sympy\integrals\rationaltools.py", line 124, in ratint_ratpart
    H = f - A.diff()*v + A*(u.diff()*v).quo(u) - B*u
  File "C:\Python27\lib\site-packages\sympy\core\decorators.py", line 75, in __sympifyit_wrapper
    return func(a, sympify(b, strict=True))
  File "C:\Python27\lib\site-packages\sympy\polys\polytools.py", line 3360, in __mul__
    return f.mul(g)
  File "C:\Python27\lib\site-packages\sympy\polys\polytools.py", line 1295, in mul
    _, per, F, G = f._unify(g)
  File "C:\Python27\lib\site-packages\sympy\polys\polytools.py", line 377, in _unify
    F = f.rep.convert(dom)
  File "C:\Python27\lib\site-packages\sympy\polys\polyclasses.py", line 277, in convert
    return DMP(dmp_convert(f.rep, f.lev, f.dom, dom), dom, f.lev)
  File "C:\Python27\lib\site-packages\sympy\polys\densebasic.py", line 530, in dmp_convert
    return dup_convert(f, K0, K1)
  File "C:\Python27\lib\site-packages\sympy\polys\densebasic.py", line 506, in dup_convert
    return dup_strip([ K1.convert(c, K0) for c in f ])
  File "C:\Python27\lib\site-packages\sympy\polys\domains\domain.py", line 85, in convert
    raise CoercionFailed("can't convert %s of type %s to %s" % (a, K0, K1))
sympy.polys.polyerrors.CoercionFailed: can't convert DMP([1, 0], ZZ) of type ZZ[_b1] to RR
[Finished in 0.3s with exit code 1]

编辑：
好吧,所以我拿出了程序正在使用的数字,并把它放在wolfram alpha中.事实证明积分不会收敛,因此误差.我想这只是一个数学错误.

解决方法:

使用符号库进行数值工作是一个非常糟糕的主意.只需使用scipy / numpy.话虽如此,对于这样一个简单的积分,你可以使用sympy.但是,您应该使用sympy表达式,而不是将所有内容转储到不透明函数中.

首先,了解python中的变量如何工作：

ig = Symbol('ig')
ig = flux(x, I, r)

在此操作之后,ig不再是符号,它只是通量的返回值.

定义所有符号,然后用它们表达.积分足够简单,可以用来处理它.

最后,像你的情况一样简单的const * x /(x-const)应该手工完成,而不是浪费在软件上.

[编辑]：我已经干净地重写了它,但由于一个错误,仍然没有正确地集成.您可以在邮件列表或问题跟踪器上报告,他们会尝试更正它.话虽如此,表达式非常简单,可以手动集成.

[EDIT2]：

In [5]: integrate(a*x/(b*x+c), x)
Out[5]: 

  ⎛         ⎛ 2        ⎞⎞
  ⎜x   c⋅log⎝b ⋅x + b⋅c⎠⎟
a⋅⎜─ - ─────────────────⎟
  ⎜b            2       ⎟
  ⎝            b        ⎠