Rstudio：找不到SingleCellExperiment中的reducedDimNames？

本人处理数据后得到

> sce <- runPCA(sce)
> set.seed(1000)
> sce <- runTSNE(sce, perplexity = 10)
> sce <- runDiffusionMap(sce)
> sce
class: SingleCellExperiment 
dim: xxxxx xxxxx 
metadata(0):
assays(2): counts logcounts
rownames(xxxxx): xxxx xxxxx ... xxxx ''
rowData names(0):
colnames(xxxxx): xxxxxxxxx xxxxxxxxxxxx ... xxxxxxxxxxxx
  xxxxxxxxxxxx
colData names(3): g n_g all
reducedDimNames(3): PCA TSNE DiffusionMap
mainExpName: NULL
altExpNames(0):

但

> head(sce@reducedDimNames$TSNE,3)
Error in h(simpleError(msg, call)) : 
  在为'head'函数选择方法时评估'x'参数出了错: "reducedDimNames"槽名不存在于"SingleCellExperiment"类别对象中
> kmeans(sce@reducedDimNames$TSNE,centers = 4)
Error in as.matrix(x) : 
  "reducedDimNames"槽名不存在于"SingleCellExperiment"类别对象中

并且运行view（sce）后找不到对象

reducedDimNames(3): PCA TSNE DiffusionMap

不知道是哪里出了问题