python - Pandas - pd.crosstab gives me incorrect classification -
i built classifier , wanted try out pd.crosstab
. however, seems give me incorrect numbers of total elements confusing , can't figure out why.
actual code:
df_confusion = pd.crosstab(pd.series(y_pred), pd.series(y_test), rownames=['predicted'], colnames= ['actual'], margins=true)
typing in jupyter notebook: df_confusion
yields
**actual** 0.0 1.0 **all** **predicted** **0.0** 6529 1951 8480 **1.0** 718 208 926 **all** 7247 2159 9406**
whereas total number of elements of each category 0 , 1 in y_pred , y_test follows:
sum(y_pred==0) equals 34264 sum(y_pred==1) equals 3514 sum(y_test==1) equals 34259 sum(y_test==0) equals 3519
however importing confusion_matrix yields expected answers
from sklearn.metrics import confusion_matrix confusion_matrix(y_test,y_pred) array([[34259, 0], [ 5, 3514]], dtype=int64)
Comments
Post a Comment