samtools獲取uniq reads

• 參考地址:
  https://www.biostars.org/p/56246/
  -q INT only include reads with mapping quality >= INT [0]
  Like for getting the unique reads (a single read mapping at one best position)
  命令以下,也有文獻報告使用的-q 2

samtools view -bq 1 file.bam > unique.bam