H2O AutoML -如何提供权重

Question

下面是我在ISLR包中设置Default日期的示例。数据不平衡，因此我对其进行了重新平衡，并仅使用GBM运行H2O AutoML。

library(ISLR)
library(h2o)
library(magrittr)
library(dplyr)
core_count <- detectCores()
h2o.init(nthreads = (core_count -1))

my_df <- Default
x <- setdiff(colnames(df_train), 'default')
y <- 'default'
    
    my_df %<>% mutate(weights = if_else(default =='No',
0.6/table(my_df$default)[[1]],0.4/table(my_df$default)[[2]]))

aml_test <- h2o.automl(x = x, y = y,
                  training_frame = as.h2o(my_df[1:8000, ]),
                  validation_frame = as.h2o(my_df[8001:10000, ]),
                  nfolds = 0, 
                  weights_column = "weights",
                  include_algos = c('GBM'),
                  seed = 12345,
                  max_runtime_secs = 1200)

它会生成以下错误：

        09:46:49.611: Skipping training of model GBM_1_AutoML_20210821_094649 due to exception:
     water.exceptions.H2OModelBuilderIllegalArgumentException: Illegal argument(s) for GBM model:
     GBM_1_AutoML_20210821_094649.  Details: ERRR on field: _min_rows: The dataset size is too 
    small to split for min_rows=1.0: must have at least 2.0 (weighted) rows, but have only 
    0.7172904568994339.
    
    09:46:49.622: Skipping training of model GBM_2_AutoML_20210821_094649 due to exception:
 water.exceptions.H2OModelBuilderIllegalArgumentException: Illegal argument(s) for GBM model: 
GBM_2_AutoML_20210821_094649.  Details: ERRR on field: _min_rows: The dataset size is too 
small to split for min_rows=10.0: must have at least 20.0 (weighted) rows, but have only 
0.7172904568994339.
    
    09:46:49.630: Skipping training of model GBM_3_AutoML_20210821_094649 due to exception: 
water.exceptions.H2OModelBuilderIllegalArgumentException: Illegal argument(s) for GBM model: 
GBM_3_AutoML_20210821_094649.  Details: ERRR on field: _min_rows: The dataset size is too 
small to split for min_rows=10.0: must have at least 20.0 (weighted) rows, but have only 
0.7172904568994339.

    
    09:46:49.637: Skipping training of model GBM_4_AutoML_20210821_094649 due to exception: 
water.exceptions.H2OModelBuilderIllegalArgumentException: Illegal argument(s) for GBM model: 
GBM_4_AutoML_20210821_094649.  Details: ERRR on field: _min_rows: The dataset size is too 
small to split for min_rows=10.0: must have at least 20.0 (weighted) rows, but have only 
0.7172904568994339.

    
    09:46:49.644: Skipping training of model GBM_5_AutoML_20210821_094649 due to exception: 
water.exceptions.H2OModelBuilderIllegalArgumentException: Illegal argument(s) for GBM model: 
GBM_5_AutoML_20210821_094649.  Details: ERRR on field: _min_rows: The dataset size is too 
small to split for min_rows=100.0: must have at least 200.0 (weighted) rows, but have only 
0.7172904568994339.

      |===================================================================================| 100%
    



       09:49:50.241: Empty leaderboard.

    AutoML was not able to build any model within a max runtime constraint of 1200 seconds,
 you may want to increase this value before retrying.The leaderboard contains zero models: 
try running AutoML for longer (the default is 1 hour).

本质上，只要提供了类的权重，它就不能与GBM一起工作。它在没有重量的情况下工作良好。它甚至没有运行整整20分钟。不会生成任何模型。

Answer 1

输出中会显示一条错误消息

Details: ERRR on field: _min_rows: The dataset size is too 
small to split for min_rows=10.0: must have at least 20.0 (weighted) rows, but have only 
0.7xxxx.

看起来你需要增加你的权重值和/或增加行数。尝试将权重列乘以10或100倍，看看是否有帮助。我怀疑如果您尝试将权重列全部设置为1，这将不是一个问题。