I have one of the column in the dataframe and I would like to remove part of the string before the 5th delimiter "." and the last "." for .txt and I don't know how to do it.
Input:
jhu-usc.edu_GBM.HumanMethylation450.6.lvl-3.TCGA-06-5415-01A-01D-1481-05.txt
jhu-usc.edu_BCD.HumanMethylation450.6.lvl-3.TCGA-06-5415-01A-01D-1482-05.txt
jhu-usc.edu_LGG.HumanMethylation450.6.lvl-3.TCGA-06-5415-01A-01D-1483-05.txt
jhu-usc.edu_LUAD.HumanMethylation450.6.lvl-3.TCGA-06-5415-01A-01D-1484-05.txt
jhu-usc.edu_LUAD.HumanMethylation450.6.lvl-3.TCGA-06-5415-01A-01D-1485-05.txt
jhu-usc.edu_BRCA.HumanMethylation450.6.lvl-3.TCGA-06-5415-01A-01D-1486-05.txt
jhu-usc.edu_GBM.HumanMethylation450.6.lvl-3.TCGA-06-5415-01A-01D-1487-05.txt
jhu-usc.edu_PRCA.HumanMethylation450.6.lvl-3.TCGA-06-5415-01A-01D-1488-05.txt
Desired output:
TCGA-06-5415-01A-01D-1481-05
TCGA-06-5415-01A-01D-1482-05
TCGA-06-5415-01A-01D-1483-05
TCGA-06-5415-01A-01D-1484-05
TCGA-06-5415-01A-01D-1485-05
TCGA-06-5415-01A-01D-1486-05
TCGA-06-5415-01A-01D-1487-05
TCGA-06-5415-01A-01D-1488-05
I tried: sapply(strsplit(as.character(df$V1), "."), '[', 1:5)
Please advice. Thank you.
Assuming that the text is fixed
sub(".*(TCGA[^.]+).*", "\\1", str1)