python自动调整单调分箱代码
时间: 2023-11-04 09:01:43 浏览: 45
很高兴能为您提供帮助!以下是一份Python自动调整单调分箱的代码示例:
```
import numpy as np
import pandas as pd
from sklearn.tree import DecisionTreeRegressor
def monotonic_binning(x, y, max_bins=10, min_samples=100):
# create initial bins
initial_bins = pd.qcut(x, q=max_bins, duplicates='drop').unique().categories
bins = initial_bins
# loop until bins are monotonic
while True:
# calculate mean y for each bin
df = pd.DataFrame({'x': x, 'y': y, 'bins': pd.cut(x, bins=bins)})
mean_y = df.groupby('bins')['y'].mean()
# check if bins are monotonic
if np.all(mean_y.diff().fillna(0) >= 0) or np.all(mean_y.diff().fillna(0) <= 0):
break
# if bins are not monotonic, merge adjacent bins with closest mean y
merge_idx = (mean_y - mean_y.shift()).abs().argmin()
bins = sorted(set(list(bins) + [mean_y.index[merge_idx], mean_y.index[merge_idx+1]]))
# check if each bin has enough samples
df = pd.DataFrame({'x': x, 'y': y, 'bins': pd.cut(x, bins=bins)})
bin_counts = df.groupby('bins')['y'].count()
if (bin_counts < min_samples).any():
# if any bin has less than min_samples, merge it with the adjacent bin with closest mean y
mean_y = df.groupby('bins')['y'].mean()
merge_idx = (mean_y - mean_y.shift()).abs().argmin()
bins = sorted(set(list(bins) + [mean_y.index[merge_idx], mean_y.index[merge_idx+1]]))
# recursively call monotonic_binning with updated bins
return monotonic_binning(x, y, max_bins=max_bins, min_samples=min_samples)
else:
return bins
# example usage
x = np.random.normal(size=1000)
y = x**2 + np.random.normal(size=1000)
bins = monotonic_binning(x, y, max_bins=10, min_samples=100)
tree = DecisionTreeRegressor(max_depth=3)
tree.fit(pd.cut(x, bins=bins).cat.codes.values.reshape(-1, 1), y)
```
请注意,这只是一个示例代码,您可能需要根据您的数据和需求进行调整。如果您有任何问题或需要进一步的帮助,请随时联系我!