在为'head'函数选择方法时评估'x'参数出了错: 'x' must be atomic ？

Question

RStudio： 

> filtered_seurat
An object of class Seurat 
37256 features across 14622 samples within 1 assay 
Active assay: RNA (37256 features, 0 variable features)

> split_seurat <- SplitObject(filtered_seurat, split.by = "orig.ident")[1:8]
> split_seurat
$lbm1
An object of class Seurat 
37256 features across 4610 samples within 1 assay 
Active assay: RNA (37256 features, 0 variable features)

$lbm2
An object of class Seurat 
37256 features across 1696 samples within 1 assay 
Active assay: RNA (37256 features, 0 variable features)

$lbm3
An object of class Seurat 
37256 features across 5890 samples within 1 assay 
Active assay: RNA (37256 features, 0 variable features)

$lbm4
An object of class Seurat 
37256 features across 982 samples within 1 assay 
Active assay: RNA (37256 features, 0 variable features)

$lc1
An object of class Seurat 
37256 features across 381 samples within 1 assay 
Active assay: RNA (37256 features, 0 variable features)

$lc2
An object of class Seurat 
37256 features across 351 samples within 1 assay 
Active assay: RNA (37256 features, 0 variable features)

$lc3
An object of class Seurat 
37256 features across 331 samples within 1 assay 
Active assay: RNA (37256 features, 0 variable features)

$lc4
An object of class Seurat 
37256 features across 381 samples within 1 assay 
Active assay: RNA (37256 features, 0 variable features)

> split_seurat <- lapply(X = split_seurat, FUN = SCTransform)

> split_seurat
$lbm1
An object of class Seurat 
48939 features across 4610 samples within 2 assays 
Active assay: SCT (11683 features, 3000 variable features)
 1 other assay present: RNA

$lbm2
An object of class Seurat 
49760 features across 1696 samples within 2 assays 
Active assay: SCT (12504 features, 3000 variable features)
 1 other assay present: RNA

$lbm3
An object of class Seurat 
47758 features across 5890 samples within 2 assays 
Active assay: SCT (10502 features, 3000 variable features)
 1 other assay present: RNA

$lbm4
An object of class Seurat 
48461 features across 982 samples within 2 assays 
Active assay: SCT (11205 features, 3000 variable features)
 1 other assay present: RNA

$lc1
An object of class Seurat 
55730 features across 381 samples within 2 assays 
Active assay: SCT (18474 features, 3000 variable features)
 1 other assay present: RNA

$lc2
An object of class Seurat 
55389 features across 351 samples within 2 assays 
Active assay: SCT (18133 features, 3000 variable features)
 1 other assay present: RNA

$lc3
An object of class Seurat 
56942 features across 331 samples within 2 assays 
Active assay: SCT (19686 features, 3000 variable features)
 1 other assay present: RNA

$lc4
An object of class Seurat 
56121 features across 381 samples within 2 assays 
Active assay: SCT (18865 features, 3000 variable features)
 1 other assay present: RNA

> features <- SelectIntegrationFeatures(split_seurat)
Error in h(simpleError(msg, call)) : 
  在为'head'函数选择方法时评估'x'参数出了错: 'x' must be atomic

如上，单细胞测序数据，出错之后，运行：

> is.atomic(split_seurat)
[1] FALSE
> is.list(split_seurat)
[1] TRUE

但是使用unlist(split_seurat)后，仍然出现：

> is.atomic(split_seurat)
[1] FALSE
> is.list(split_seurat)
[1] TRUE

运行SelectIntegrationFeatures() 还是报错。

接下来使用内置数据进行测试：

> devtools::install_github('satijalab/seurat-data')
> library(SeuratData)
> AvailableData()
> InstallData("panc8")
> data("panc8")
> panc8
An object of class Seurat 
34363 features across 14890 samples within 1 assay 
Active assay: RNA (34363 features, 0 variable features)

> pancreas.list <- SplitObject(panc8, split.by = "tech")[1:2]
> pancreas.list
$celseq
An object of class Seurat 
34363 features across 1004 samples within 1 assay 
Active assay: RNA (34363 features, 0 variable features)

$celseq2
An object of class Seurat 
34363 features across 2285 samples within 1 assay 
Active assay: RNA (34363 features, 0 variable features)

> pancreas.list <- lapply(X = pancreas.list, FUN = SCTransform)
> pancreas.list
$celseq
An object of class Seurat 
51110 features across 1004 samples within 2 assays 
Active assay: SCT (16747 features, 3000 variable features)
 1 other assay present: RNA

$celseq2
An object of class Seurat 
51501 features across 2285 samples within 2 assays 
Active assay: SCT (17138 features, 3000 variable features)
 1 other assay present: RNA

> features <- SelectIntegrationFeatures(pancreas.list)

以上测试数据集并没有报错，但是运行：

​
> is.atomic(pancreas.list)
[1] FALSE
> is.list(pancreas.list)
[1] TRUE

​

 is.atomic(pancreas.list) 竟然也是FALSE。

不解。。。

Answer 1

看不懂