Filter row names based on string length [duplicate]

Question

I want to filter rows that contain rownames longer than 35 and shorter than 10. I was looking at the nchar function.

                                    79_CGTACG.collapsed.gz 80_ACAGTG.collapsed.gz
CACCCGCACGTATAGACGGACA                                   0                      0
GTGCTGATGTCCTTGGCAGGCTTCGGCCGTCCGGC                      0                      0
CGTGGAACCTG                                              0                      0
TAATGGTCATTAG                                            2                      1
GGCGATGCGGGATGAACCGAAC                                   0                      0
AAGGATGT                                                 0                      0

Answer 1

I think your idea to use nchar() is good. This can be applied to rownames() and combined with a logical susetting of the data frame:

df1[nchar(rownames(df1)) > 35 | nchar(rownames(df1)) < 10,]
#         X79_CGTACG.collapsed.gz X80_ACAGTG.collapsed.gz
#AAGGATGT                       0                       0

data

 df1 <- structure(list(X79_CGTACG.collapsed.gz = c(0L, 0L, 0L, 2L, 0L, 
0L), X80_ACAGTG.collapsed.gz = c(0L, 0L, 0L, 1L, 0L, 0L)), 
 .Names = c("X79_CGTACG.collapsed.gz", "X80_ACAGTG.collapsed.gz"), 
  class = "data.frame", row.names = c("CACCCGCACGTATAGACGGACA", 
  "GTGCTGATGTCCTTGGCAGGCTTCGGCCGTCCGGC", "CGTGGAACCTG", "TAATGGTCATTAG", 
 "GGCGATGCGGGATGAACCGAAC", "AAGGATGT"))