删除除一列以外的所有列均为零的行很简单:

Removing rows where all columns except one are zeros is straight-forward:

sample_DT[ rowSums(sample_DT[,-1]) > 0, ]
#         id sample1 sample2
# 1:  GENE_1       1       2
# 2:  GENE_2       2       1
# 3:  GENE_3       3       4
# 4:  GENE_5       5       3
# 5:  GENE_6       1       2
# 6:  GENE_7       2       1
# 7:  GENE_8       3       4
# 8: GENE_10       5       3