H2O AutoML - 如何提供权重答案

【问题标题】：H2O AutoML - how to provide weightsH2O AutoML - 如何提供权重
【发布时间】：2023-03-16 03:02:01
【问题描述】：

这是我的示例，其中 Default 从 ISLR 包中设置日期。数据不平衡，因此我重新平衡它并仅使用 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)

它会产生以下错误：

        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，只要提供类的权重，它就不适用于 GBM。没有重量也能正常工作。它甚至没有运行整整 20 分钟。没有生成模型。

【问题讨论】：

标签： h2o weighted automl gbm

【解决方案1】：

您的输出中显示了一条错误消息

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.

您似乎需要增加权重值和/或增加行数。尝试将您的体重列乘以 10 或 100 倍，看看是否有帮助。如果您尝试将权重列设置为所有列，我怀疑这不会成为问题。

【讨论】：