r - 插入符号中的并行处理不适用于 R 2.13.0

Question

我正在使用 R 包 caret 并且并行处理不起作用。如果我尝试从 train 函数运行示例:

library(mlbench)
data(BostonHousing)

library(doMC)
registerDoMC(2)

## NOTE: don't run models form RWeka when using
### multicore. The session will crash.

## The code for train() does not change:
set.seed(1)
usingMC <-  train(medv ~ .,
                  data = BostonHousing, 
                  "glmboost")

我收到以下错误:

Error in names(resamples) <- gsub("^\\.", "", names(resamples)) : 
  attempt to set an attribute on NULL

我使用的是 MacBook Pro，2011 年初机型，配备 2.3GHz Intel Core i5 和 Mac OS X 10.6.8。

R session 信息:

R version 2.13.0 (2011-04-13) Platform: x86_64-apple-darwin9.8.0/x86_64 (64-bit)

attached base packages: [1] stats graphics grDevices utils
datasets methods base

other attached packages: [1] caret_5.13-20 cluster_1.14.2 reshape_0.8.4 plyr_1.7.1 lattice_0.19-33 mlbench_2.1-0
doMC_1.2.3 multicore_0.1-7 [9] foreach_1.3.2 codetools_0.2-8 iterators_1.0.5

loaded via a namespace (and not attached): [1] compiler_2.13.0 grid_2.13.0 rpart_3.1-51 tools_2.13.0

我能做些什么来解决这个问题吗？

Answer 1

1. 可能很难找到可以重现您的错误的人:有了

   > sessionInfo ()
   R version 2.15.0 (2012-03-30)
   Platform: x86_64-pc-linux-gnu (64-bit)
   

   [...剪断...]

   other attached packages:
    [1] mboost_2.1-2    caret_5.15-023  cluster_1.14.2  reshape_0.8.4  
    [5] plyr_1.7.1      lattice_0.20-6  doMC_1.2.5      multicore_0.1-7
    [9] iterators_1.0.6 foreach_1.4.0   mlbench_2.1-0          
   
   loaded via a namespace (and not attached):
   [1] codetools_0.2-8  compiler_2.15.0  grid_2.15.0      Matrix_1.0-6    
   [5] splines_2.15.0   survival_2.36-14 tools_2.15.0    
   

   有效。

2. 这意味着您可能需要深入研究代码:traceback () 和 debug () 应该会有所帮助。