Error in *tmp*$samples : $ operator is invalid for atomic vectors

> x <- as.matrix(read.delim("E:/bioinformatic/RNAseq/GSE168008_raw_count.txt", sep ="" ,row.names = 1))
> dgelist <-DGEList(counts = x)
> dim(x)
[1] 25702    10
> samplenames <- substring(colnames(x), 1, nchar(colnames(x))) 
> samplenames
 [1] "BLJ1_align"  "BLJ2_align"  "BLJ3_align"  "BLJ4_align"  "BLJ5_align" 
 [6] "BLJ6_align"  "BLJ7_align"  "BLJ8_align"  "BLJ9_align"  "BLJ10_align"
> colnames(x) <- samplenames 
> group <- as.factor(c("BM_MSC", "BM_MSC", "BM_MSC", "BM_MSC", "BM_MSC", "BM_MSC_act", 
+                      "BM_MSC_act", "BM_MSC_act", "BM_MSC_act", "BM_MSC_act"))
> x$samples$group <- group
Error in `*tmp*`$samples : $ operator is invalid for atomic vectors

Many thanks for your help!

I believe you want

> x <- as.matrix(read.delim("E:/bioinformatic/RNAseq/GSE168008_raw_count.txt", sep ="" ,row.names = 1))
> samplenames <- substring(colnames(x), 1, nchar(colnames(x))) 
> samplenames
 [1] "BLJ1_align"  "BLJ2_align"  "BLJ3_align"  "BLJ4_align"  "BLJ5_align" 
 [6] "BLJ6_align"  "BLJ7_align"  "BLJ8_align"  "BLJ9_align"  "BLJ10_align"
> colnames(x) <- samplenames 
> group <- as.factor(c("BM_MSC", "BM_MSC", "BM_MSC", "BM_MSC", "BM_MSC", "BM_MSC_act", 
+                      "BM_MSC_act", "BM_MSC_act", "BM_MSC_act", "BM_MSC_act"))
> dgelist <-DGEList(counts = x, group = group)

Your order of operation is off, and you are trying to add the group variable to your matrix of counts rather than the DGEList you have constructed. It's easier to add the groups as part of the DGEList call anyway.