[Bioc-devel] inconsistent metadata when deleting a column from a DataFrame

[Alejandro Reyes]

Hello,

I noticed that when I delete a column from a DataFrame by assigning it to NULL, the column is deleted from the DataFrame but the corresponding element-wise metadata is not deleted. 

> library(S4Vectors)                                                                                                                             
!> df <- DataFrame(A=1:10, B=1:10 )                                                                                                               
 > mcols( df )$colNum <- sprintf( "col num %d", seq_len( ncol( df ) ) )                                                                           
 > df[["B"]] <- NULL                                                                                                                              
 > ncol(df)                                                                                                                                       
 [1] 1
 > nrow(mcols(df))                                                                                                                                
 [1] 2

After doing this, I get the following error when I try to assign new columns:

> df$C <- 1:10                                                                                                                                 
 Error in V_recycle(value, x, x_what = "value", skeleton_what = "x") :
   'NROW(value)' is greater than 'length(x)'

Is this behavoir intended? or am I missing something?

> sessionInfo()
 R version 3.4.2 (2017-09-28)
 Platform: x86_64-apple-darwin15.6.0 (64-bit)
 Running under: macOS High Sierra 10.13.1

 Matrix products: default
 BLAS: /Library/Frameworks/R.framework/Versions/3.4/Resources/lib/libRblas.0.dylib
 LAPACK: /Library/Frameworks/R.framework/Versions/3.4/Resources/lib/libRlapack.dylib

 locale:
 [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

 attached base packages:
 [1] parallel  stats4    stats     graphics  grDevices utils     datasets
 [8] methods   base
other attached packages:
 [1] SummarizedBenchmark_0.99.0 data.table_1.10.4-3        stringr_1.2.0             
 [4] rlang_0.1.4                UpSetR_1.3.3               SummarizedExperiment_1.8.0
 [7] DelayedArray_0.4.1         matrixStats_0.52.2         Biobase_2.38.0            
[10] GenomicRanges_1.30.0       GenomeInfoDb_1.14.0        IRanges_2.12.0            
[13] S4Vectors_0.16.0           BiocGenerics_0.24.0        tidyr_0.7.2               

loaded via a namespace (and not attached):
 [1] Rcpp_0.12.13            XVector_0.18.0          magrittr_1.5            zlibbioc_1.24.0        
 [5] munsell_0.4.3           colorspace_1.3-2        lattice_0.20-35         plyr_1.8.4             
 [9] tools_3.4.2             grid_3.4.2              gtable_0.2.0            lazyeval_0.2.1         
[13] tibble_1.3.4            Matrix_1.2-11           gridExtra_2.3           GenomeInfoDbData_0.99.1
[17] purrr_0.2.4             ggplot2_2.2.1           bitops_1.0-6            RCurl_1.95-4.8         
[21] glue_1.2.0              stringi_1.1.5           compiler_3.4.2          scales_0.5.0        



Best regards,
—
Alejandro Reyes, Ph.D.
Research Fellow, Irizarry Lab
Dana-Farber Cancer Institute
Harvard T.H. Chan School of Public Health
Boston, USA