Python 使用贝叶斯优化时，队列为空

我正在使用python库“bayes_opt”使用贝叶斯优化来优化NN的超参数，但出现了一个错误

~\Miniconda3\envs\tensorflow\lib\site packages\bayes\u opt\bayesian\u optimization.py 在下一步中（自我） 25如果self.empty： --->26 raise StopIteration（“队列为空，没有更多要检索的对象”） 27 obj=self.\u队列[0]

StopIteration:队列为空，没有更多要检索的对象

我的代码如下：

from bayes_opt import BayesianOptimization
import time

# Supress NaN warnings, see: https://stackoverflow.com/questions/34955158/what-might-be-the-cause-of-invalid-value-encountered-in-less-equal-in-numpy
import warnings
warnings.filterwarnings("ignore",category =RuntimeWarning)


# Bounded region of parameter space
pbounds = {'dropout': (0.0, 0.499),
           'lr': (0.0, 0.1),
           'neuronPct': (0.01, 1),
           'neuronShrink': (0.01, 1)
          } 

optimizer = BayesianOptimization(
    f=evaluate_network,
    pbounds=pbounds,
    verbose=2,  # verbose = 1 prints only when a maximum is observed, verbose = 0 is silent
    random_state=1,
)

start_time = time.time()
optimizer.maximize(init_points=10, n_iter=100,)
time_took = time.time() - start_time

print(optimizer.max)

输出如下：

|   iter    |  target   |  dropout  |    lr     | neuronPct | neuron... |
-------------------------------------------------------------------------
|  1        | -0.5718   |  0.2081   |  0.07203  |  0.01011  |  0.3093   |
|  2        | -0.5906   |  0.07323  |  0.009234 |  0.1944   |  0.3521   |
|  3        | -2.475    |  0.198    |  0.05388  |  0.425    |  0.6884   |
|  4        | -0.5708   |  0.102    |  0.08781  |  0.03711  |  0.6738   |
|  5        | -0.5749   |  0.2082   |  0.05587  |  0.149    |  0.2061   |
|  6        | -2.487    |  0.3996   |  0.09683  |  0.3203   |  0.6954   |
|  7        | -0.5669   |  0.4373   |  0.08946  |  0.09419  |  0.04866  |
|  8        | -0.5701   |  0.08475  |  0.08781  |  0.1074   |  0.4269   |
|  9        | -0.607    |  0.478    |  0.05332  |  0.695    |  0.3224   |
|  10       | -0.581    |  0.3426   |  0.08346  |  0.02811  |  0.7526   |
|  11       | -0.7295   |  0.1606   |  0.0      |  1.0      |  0.01     |
|  12       | -0.7131   |  0.499    |  0.0      |  0.607    |  0.01     |
|  13       | -0.7044   |  0.0      |  0.0      |  0.01     |  0.01     |
|  14       | -0.5872   |  0.04935  |  0.01347  |  0.4728   |  0.4246   |
|  15       | -0.5665   |  0.0      |  0.1      |  0.5566   |  0.01     |
|  16       | -0.9658   |  0.0      |  0.0      |  1.0      |  0.4938   |
|  17       | -0.9074   |  0.0      |  0.0      |  0.01     |  1.0      |
|  18       | -2.464    |  0.499    |  0.1      |  1.0      |  0.1975   |
|  19       | -0.9505   |  0.499    |  0.0      |  1.0      |  1.0      |
|  20       |  nan      |  0.0      |  0.1      |  1.0      |  1.0      |  

注意输出表最后一行的“nan”

---

提前谢谢。

同样的事情刚刚发生在我身上。我看到这是一个老帖子，所以没有希望很快得到解决

我设法将其缩小到以下范围：如果pbounds间隔太小，就会发生这种情况。我使pbound间隔稍微大一点，它就停止了

---

这对我来说很有效，但我希望将来有人能解决这个问题。错误似乎出现在sklearn中。

我最近在包中使用bayes_opt时遇到了类似的问题

要解决“StopIteration:队列为空…”错误，我必须从以下位置修改pbounds参数：

pbounds = {'daily_prior': (2, -2), 'yearly_prior': (2, -2)}

到

我已经检查了大多数（如果不是全部的话）bayes_opt示例，到目前为止，它们都有这个

{'param'：（最小值，最大值）}

表单

我在bayes_opt存储库中添加了这个答案

这不会修正原始问题中的错误，但我希望它能帮助某些人

---

另外，以下是我收到的完整错误消息：

Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/bayes_opt/bayesian_optimization.py", line 181, in maximize
    x_probe = next(self._queue)
  File "/usr/local/lib/python3.8/site-packages/bayes_opt/bayesian_optimization.py", line 25, in __next__
    raise StopIteration("Queue is empty, no more objects to retrieve.")
StopIteration: Queue is empty, no more objects to retrieve.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "bayes_opt_prophet_bounds_test.py", line 43, in <module>
    optimizer.maximize(
  File "/usr/local/lib/python3.8/site-packages/bayes_opt/bayesian_optimization.py", line 184, in maximize
    x_probe = self.suggest(util)
  File "/usr/local/lib/python3.8/site-packages/bayes_opt/bayesian_optimization.py", line 133, in suggest
    suggestion = acq_max(
  File "/usr/local/lib/python3.8/site-packages/bayes_opt/util.py", line 58, in acq_max
    res = minimize(lambda x: -ac(x.reshape(1, -1), gp=gp, y_max=y_max),
  File "/usr/local/lib/python3.8/site-packages/scipy/optimize/_minimize.py", line 617, in minimize
    return _minimize_lbfgsb(fun, x0, args, jac, bounds,
  File "/usr/local/lib/python3.8/site-packages/scipy/optimize/lbfgsb.py", line 294, in _minimize_lbfgsb
    raise ValueError("LBFGSB - one of the lower bounds is greater than an upper bound.")
ValueError: LBFGSB - one of the lower bounds is greater than an upper bound.

回溯（最近一次呼叫最后一次）：
文件“/usr/local/lib/python3.8/site packages/bayes\u opt/bayesian\u optimization.py”，第181行，在第页
x_probe=next（self._队列）
文件“/usr/local/lib/python3.8/site packages/bayes\u opt/bayesian\u optimization.py”，第25行，下一步__
引发StopIteration（“队列为空，没有更多对象可检索。”）
StopIteration:队列为空，没有更多要检索的对象。
在处理上述异常期间，发生了另一个异常：
回溯（最近一次呼叫最后一次）：
文件“bayes_opt_prophet_bounds_test.py”，第43行，在
优化器。最大化(
文件“/usr/local/lib/python3.8/site packages/bayes\u opt/bayesian\u optimization.py”，第184行，在第页
x_probe=self.suggest（util）
文件“/usr/local/lib/python3.8/site packages/bayes\u opt/bayesian\u optimization.py”，第133行，建议
建议=acq_最大值(
文件“/usr/local/lib/python3.8/site packages/bayes_opt/util.py”，第58行，在acq_max中
res=最小化（λx:-ac（x.重塑（1，-1），gp=gp，y_max=y_max），
文件“/usr/local/lib/python3.8/site packages/scipy/optimize/_minimize.py”，最小化中的第617行
返回_最小化_lbfgsb（fun、x0、args、jac、bounds、，
文件“/usr/local/lib/python3.8/site packages/scipy/optimize/lbfgsb.py”，第294行，在lbfgsb中
raise VALUETERROR（“LBFGSB-其中一个下限大于上限。”）
ValueError:LBFGSB-其中一个下限大于上限。

init_points arg

似乎是我的问题，我从10开始，一直到45来解决它

最大化（初始点=45，n\u iter=20）

---

这与您的结果有关。正如您所看到的，行中的目标是np.nan，您的错误是“队列为空，没有更多要检索的对象”，我猜函数已用完您的数据点。但没有什么是确定的，我想您已阅读此包的源代码。

Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/bayes_opt/bayesian_optimization.py", line 181, in maximize
    x_probe = next(self._queue)
  File "/usr/local/lib/python3.8/site-packages/bayes_opt/bayesian_optimization.py", line 25, in __next__
    raise StopIteration("Queue is empty, no more objects to retrieve.")
StopIteration: Queue is empty, no more objects to retrieve.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "bayes_opt_prophet_bounds_test.py", line 43, in <module>
    optimizer.maximize(
  File "/usr/local/lib/python3.8/site-packages/bayes_opt/bayesian_optimization.py", line 184, in maximize
    x_probe = self.suggest(util)
  File "/usr/local/lib/python3.8/site-packages/bayes_opt/bayesian_optimization.py", line 133, in suggest
    suggestion = acq_max(
  File "/usr/local/lib/python3.8/site-packages/bayes_opt/util.py", line 58, in acq_max
    res = minimize(lambda x: -ac(x.reshape(1, -1), gp=gp, y_max=y_max),
  File "/usr/local/lib/python3.8/site-packages/scipy/optimize/_minimize.py", line 617, in minimize
    return _minimize_lbfgsb(fun, x0, args, jac, bounds,
  File "/usr/local/lib/python3.8/site-packages/scipy/optimize/lbfgsb.py", line 294, in _minimize_lbfgsb
    raise ValueError("LBFGSB - one of the lower bounds is greater than an upper bound.")
ValueError: LBFGSB - one of the lower bounds is greater than an upper bound.