list comprehension return a list and sum over in loop

[KK Sasa]

Peter Otten於 2014年12月12日星期五UTC+8下午8時32分55秒寫道：
> Jussi Piitulainen wrote:
> 
> > KK Sasa writes:
> > 
> >> def p(x,t,point,z,obs):
> >>     d = x[0]
> >>     tau = [0]+[x[1:point]]
> >>     a = x[point:len(x)]
> >>     at = sum(i*j for i, j in zip(a, t))
> >>     nu = [exp(z[k]*(at-d)-sum(tau[k])) for k in xrange(point)]
> >>     de = sum(nu, axis=0)
> >>     probability = [nu[k]/de for k in xrange(point)]
> >>     return probability[obs]
> > 
> > I must be blind, but this looks like computing a whole probability
> > distribution and then throwing almost all of it away.
> > 
> > Can't this just return nu[obs]/de?
> > 
> > The expression for tau also seems weird to me. Isn't it equivalent to
> > [0, x[1:point]], a two-element list with the second element a list?
> > How can sum(tau[k]) work at all then, for any k > 1?
> 
> Also, after adding 
> 
> from numpy.random import seed
> 
> to the code I run into the next problem:
> 
> Traceback (most recent call last):
>   File "hessian.py", line 34, in <module>
>     re = [d2(x,t[k],2,z,1) for k in range_people]
>   File "/home/petto/.local/lib/python2.7/site-packages/ad/__init__.py", line 
> 1114, in hess
>     return func(xa, *args).hessian([xa])
>   File "hessian.py", line 26, in p
>     nu = [exp(z[k]*(at-d)-sum(tau[k])) for k in xrange(point)]
> TypeError: 'int' object is not iterable
> 
> OP: Optimizations only make sense when you can start from a known-good base. 
> You should sort out the logic of your problem (we probably can't help you 
> with that), then fix the bugs in your code and only then revisit the "speed 
> issue".

I have no idea why you added "from numpy.random import seed" to this syntax. Even I added that, my python didn't complain any bugs inside. Maybe your ad package was not be installed correctly?