Python SciPy optimize.fmin VALUERROR:从零大小数组到无标识的最大缩减操作
更新2:一个更好的标题(现在我理解了这个问题)是: scipy optimize.fmin中输入的正确语法是什么 更新:已请求可运行代码,因此函数定义已替换为可运行代码。样本输入数据已硬编码为numpy数组“data” 我正试图用scipy优化一个函数,但我真的被卡住了,必须寻求帮助。一个零长度数组正在传递给优化器中的一个方法,我无法理解为什么,也无法理解如何克服这个问题 此代码尝试执行的操作的简要概述:Python SciPy optimize.fmin VALUERROR:从零大小数组到无标识的最大缩减操作,python,arrays,numpy,scipy,Python,Arrays,Numpy,Scipy,更新2:一个更好的标题(现在我理解了这个问题)是: scipy optimize.fmin中输入的正确语法是什么 更新:已请求可运行代码,因此函数定义已替换为可运行代码。样本输入数据已硬编码为numpy数组“data” 我正试图用scipy优化一个函数,但我真的被卡住了,必须寻求帮助。一个零长度数组正在传递给优化器中的一个方法,我无法理解为什么,也无法理解如何克服这个问题 此代码尝试执行的操作的简要概述: 由单个观测值“r”组成的给定数据集“数据” 估计最有可能产生“数据”的参数“m”的值
- 由单个观测值“r”组成的给定数据集“数据”
- 估计最有可能产生“数据”的参数“m”的值
- 对于给定的m,计算观察“数据”中每个“r”的概率p(r | m)
- 对于给定的m,计算“m”生成数据的概率P(m |数据)李>
- 定义用于optimize.fmin的辅助函数李>
- 使用SciPy optimize.fmin确定最大化辅助对象(m |数据)的m
#!/usr/bin/env python2.7
import numpy as np
from scipy import optimize
def p_of_r(m, r): ## this calculates p(r|m) for each datum r
r_range = np.arange(0, r+1, 1, dtype='int')
p_r = []
p_r = np.array([0.0 for a in r_range])
for x in r_range:
if x == 0:
p_r[x] = np.exp(-1 * m)
else:
total = 0.0
for y in np.arange(0, x, 1, dtype='int'):
current = ( p_r[y] ) / (x - y + 1)
total = current + total
p_r[x] = ( m / x ) * total
return p_r
def likelihood_function(m, *data): # calculates P(m|data) using entire data set
p_r = p_of_r(m, np.ma.max(data))
p_r_m = np.array([p_r[y] for y in data])
bigP = np.prod(p_r_m)
return bigP
def main():
data = np.array( [10, 10, 7, 19, 9, 23, 26, 7, 164, 16 ] )
median_r = np.median(data)
def Drake(m):
return median_r / m - np.log(m)
m_initial = optimize.broyden1(Drake, 1)
def helper(x, *args):
helper_value = -1 * likelihood_function(x, *args)
return helper_value
# here is the actual optimize.fmin
fmin_result = optimize.fmin(helper, x0=[m_initial], args=data)
print fmin_result
# for i in np.arange(0.0, 25.0, 0.1):
# print i, helper(i, data)
if __name__ == "__main__" : main()
错误本身:
ValueError:从零大小数组到没有标识的最大缩减操作
下面提供了回溯
ValueError Traceback (most recent call last)
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/utils/py3compat.pyc in execfile(fname, *where)
176 else:
177 filename = fname
--> 178 __builtin__.execfile(filename, *where)
/Users/deyler/bin/MSS-likelihood-minimal.py in <module>()
43 print fmin_result
44
---> 45 if __name__ == "__main__" : main()
/Users/deyler/bin/MSS-likelihood-minimal.py in main()
40
41
---> 42 fmin_result = optimize.fmin(helper, x0=[m_initial], args=data)
43 print fmin_result
44
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/scipy/optimize/optimize.pyc in fmin(func, x0, args, xtol, ftol, maxiter, maxfun, full_output, disp, retall, callback)
371 'return_all': retall}
372
--> 373 res = _minimize_neldermead(func, x0, args, callback=callback, **opts)
374 if full_output:
375 retlist = res['x'], res['fun'], res['nit'], res['nfev'], res['status']
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/scipy/optimize/optimize.pyc in _minimize_neldermead(func, x0, args, callback, xtol, ftol, maxiter, maxfev, disp, return_all, **unknown_options)
436 if retall:
437 allvecs = [sim[0]]
--> 438 fsim[0] = func(x0)
439 nonzdelt = 0.05
440 zdelt = 0.00025
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/scipy/optimize/optimize.pyc in function_wrapper(*wrapper_args)
279 def function_wrapper(*wrapper_args):
280 ncalls[0] += 1
--> 281 return function(*(wrapper_args + args))
282
283 return ncalls, function_wrapper
/Users/deyler/bin/MSS-likelihood-minimal.py in helper(x, *args)
33 m_initial = optimize.broyden1(Drake, 1)
34 def helper(x, *args):
---> 35 helper_value = -1 * likelihood_function(x, *args)
36 return helper_value
37
/Users/deyler/bin/MSS-likelihood-minimal.py in likelihood_function(m, *data)
21
22 def likelihood_function(m, *data):
---> 23 p_r = p_of_r(m, np.ma.max(data))
24 p_r_m = np.array([p_r[y] for y in data])
25 bigP = np.prod(p_r_m)
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy/ma/core.pyc in max(obj, axis, out, fill_value)
5899 # If obj doesn't have a max method,
5900 # ...or if the method doesn't accept a fill_value argument
-> 5901 return asanyarray(obj).max(axis=axis, fill_value=fill_value, out=out)
5902 max.__doc__ = MaskedArray.max.__doc__
5903
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy/ma/core.pyc in max(self, axis, out, fill_value)
5159 # No explicit output
5160 if out is None:
-> 5161 result = self.filled(fill_value).max(axis=axis, out=out).view(type(self))
5162 if result.ndim:
5163 # Set the mask
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy/core/_methods.pyc in _amax(a, axis, out, keepdims)
8 def _amax(a, axis=None, out=None, keepdims=False):
9 return um.maximum.reduce(a, axis=axis,
---> 10 out=out, keepdims=keepdims)
11
12 def _amin(a, axis=None, out=None, keepdims=False):
ValueError: zero-size array to reduction operation maximum which has no identity
ValueError回溯(最近一次调用)
/execfile(fname,*其中)中的Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/utils/py3compat.pyc
176.其他:
177 filename=fname
-->178 \uuuu内置\uuuuu.execfile(文件名,*其中)
/Users/deyler/bin/MSS-likelion-minimal.py in()
43打印fmin_结果
44
--->45如果uuuu name uuuuuu==“uuuuu main”:main()
/main()中的Users/deyler/bin/MSS-likelion-minimal.py
40
41
--->42 fmin_result=optimize.fmin(helper,x0=[m_initial],args=data)
43打印fmin_结果
44
/fmin中的Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/scipy/optimize/optimize.pyc(func、x0、args、xtol、ftol、maxiter、maxfun、full_输出、disp、retall、回调)
371“返回所有”:retail}
372
-->373 res=\u最小化\u neldermead(func,x0,args,callback=callback,**选项)
374如果满输出:
375 retlist=res['x'],res['fun'],res['nit'],res['nfev'],res['status']
/_minimize_neldermead中的Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/scipy/optimize/optimize.pyc(func、x0、args、callback、xtol、ftol、maxiter、maxfev、disp、return_all、**未知_选项)
436如果报复:
437 allvecs=[sim[0]]
-->438 fsim[0]=func(x0)
439非Zdelt=0.05
440 zdelt=0.00025
/函数_wrapper(*wrapper_args)中的Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/scipy/optimize/optimize.pyc
279 def函数包装器(*包装器参数):
280 nCall[0]+=1
-->281返回函数(*(包装器参数+参数))
282
283返回NCALL,函数包装器
/帮助程序中的Users/deyler/bin/MSS-likelion-minimal.py(x,*args)
33 m_初始=优化.broyden1(德雷克,1)
34 def辅助程序(x,*参数):
--->35 helper_值=-1*似然函数(x,*args)
36返回值
37
/似然函数中的Users/deyler/bin/MSS-likelion-minimal.py(m,*数据)
21
22 def似然函数(m,*数据):
--->23 p_r=p_/r(m,np.ma.max(数据))
24 p_r_m=np.数组([p_r[y]表示数据中的y])
25 bigP=np.prod(p\u r\m)
/max中的Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy/ma/core.pyc(obj、axis、out、fill_值)
5899#如果obj没有max方法,
5900#…或者如果该方法不接受fill#u值参数
->5901返回asanyarray(obj).max(轴=轴,填充值=填充值,输出=输出)
5902 max.\uuuuu doc\uuuuu=MaskedArray.max.\uuuu doc__
5903
/max中的Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy/ma/core.pyc(self、axis、out、fill_值)
5159#无明确输出
5160如果输出为无:
->5161结果=自填充(填充值)。最大值(轴=轴,输出=输出)。视图(类型(自))
5162如果result.ndim:
5163#设置遮罩
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy/core//u methods.pyc in\u amax(a、axis、out、keepdims)
8 def_amax(a,axis=None,out=None,keepdims=False):
9返回最大值减小(a,轴=轴,
--->10 out=out,keepdims=keepdims)
11
12 def_amin(a,axis=None,out=None,keepdims=False):
ValueError:从零大小数组到没有标识的最大缩减操作
正确的是:
args:tuple,可选
Extra arguments passed to func, i.e. f(x,*args).
预计会有下一个结果吗
Optimization terminated successfully.
Current function value: -0.000000
Iterations: 16
Function evaluations: 32
[ 5.53610656]
请在获取错误时提供您正在处理的示例数据。您的
数据似乎为空。不幸的是,我们不知道数据从哪里来。此外,错误消息与代码不匹配。当剥离或简化代码时,请尽最大努力构造一个最小的、可运行的示例,在运行时演示您发布的错误。如果您不能这样做,请至少使其与错误消息保持一致。@alko,@user2357112:Runnable,错误生成代码已发布<代码>数据
已明确定义。如果数据
看起来是空的,那么我对优化器的输入做错了。我明白了。args=(tuple),因此括号是必需的。谢谢,这已经花了我两天时间了。@dangene
Optimization terminated successfully.
Current function value: -0.000000
Iterations: 16
Function evaluations: 32
[ 5.53610656]