形状绘图出错

如何解决形状绘图出错

X = df.copy()

# Save and drop labels
y = df['class']
X = X.drop('class',axis=1)
cat_features = list(range(0,X.shape[1]))
model = CatBoostClassifier(iterations=2000,learning_rate=0.1,random_seed=12)
model.fit(X,y,verbose=False,plot=False)

explainer = shap.Explainer(model)
shap_values = explainer(X)

shap.force_plot(explainer.expected_value,shap_values[0:5,:],X.iloc[0:5,plot_cmap="DrDb")

---------------------------------------------------------------------------
AssertionError                            Traceback (most recent call last)
<ipython-input-170-ba1eca12b9ed> in <module>
----> 1 shap.force_plot(10,plot_cmap="DrDb")

~\anaconda3\lib\site-packages\shap\plots\_force.py in force(base_value,shap_values,features,feature_names,out_names,link,plot_cmap,matplotlib,show,figsize,ordering_keys,ordering_keys_time_format,text_rotation,contribution_threshold)
    101 
    102     if type(shap_values) != np.ndarray:
--> 103         return visualize(shap_values)
    104 
    105     # convert from a DataFrame or other types

~\anaconda3\lib\site-packages\shap\plots\_force.py in visualize(e,min_perc)
    343             return AdditiveForceArrayVisualizer(e,plot_cmap=plot_cmap,ordering_keys=ordering_keys,ordering_keys_time_format=ordering_keys_time_format)
    344     else:
--> 345         assert False,"visualize() can only display Explanation objects (or arrays of them)!"
    346 
    347 class BaseVisualizer:

AssertionError: visualize() can only display Explanation objects (or arrays of them)!

试图用 shap 和我的数据绘图，但出错了，我实际上不明白为什么。没有发现任何关于这方面的信息。请解释如何避免此错误？

explainer.expected_value
-5.842052267820879

解决方法

您应该将最后一行更改为：shap.force_plot(explainer.expected_value,shap_values.values[0:5,:],X.iloc[0:5,plot_cmap="DrDb")

通过调用 shap_values.values 而不仅仅是 shap_values，因为 shap_values 保存了 shapley 值，base_values 和 data 。在检查变量之前，我遇到了同样的问题。