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我有一段由于各种原因可能会失败的数字代码，我想用 numpy.NAN 替换输出值，这样事情就会继续发展。我试图将对 brentq 的调用包装在 try:except: 语句中，但它仍然使我的代码因同一个异常而崩溃。

def someotherfunction(stuff):
    self.energy2ph = lambda e: self.brentq_fails_to_NAN(ph2offset_energy, 0., max_ph, args=(e,))    
def brentq_fails_to_NAN(self, *args):
    ''' this simply calls scipy.optimize.brentq with the exact same arguments, 
    but in the case of an error it returns numpy.NAN instead of throwing an exception '''
    try:
        return scipy.optimize.brentq(*args)
    except:
        print 'returning numpy.NAN instead of throwing an exception for energy2ph'
        return numpy.NAN

我得到一个回溯，但有一个异常可以追溯到我的 try 语句。我的理解是应该在那种情况下运行 except: 语句下的代码

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/mass/calibration/energy_calibration.pyc in name2ph(self, name)
    257 
    258     def brentq_fails_to_NAN(self, *args):
--> 259         try:
    260             return scipy.optimize.brentq(*args)
    261         except:

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/mass/calibration/energy_calibration.pyc in <lambda>(e)
    252         max_ph = 1.3*self._ph[-1]
    253         ph2offset_energy = lambda ph, eoffset: self.ph2energy(ph)-eoffset
--> 254 #        self.energy2ph = lambda e: scipy.optimize.brentq(ph2offset_energy, 0., max_ph, args=(e,))
    255         self.energy2ph = lambda e: self.brentq_fails_to_NAN(ph2offset_energy, 0., max_ph, args=(e,))
    256 

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/scipy/optimize/zeros.pyc in brentq(f, a, b, args, xtol, rtol, maxiter, full_output, disp)
    387     if type(args) != type(()) :
    388         args = (args,)
--> 389     r = _zeros._brentq(f,a,b,xtol,maxiter,args,full_output,disp)
    390     return results_c(full_output, r)
    391 

ValueError: f(a) and f(b) must have different signs
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1 回答 1

0

在这种情况下可能会吞下一些异常，请试试这个

except Exception:
        print 'returning numpy.NAN instead of throwing an exception for energy2ph'
        return numpy.NAN
于 2013-03-12T23:10:26.407 回答