Removing rows if certain elements are found in character string
On Jul 2, 2012, at 6:48 PM, Claudia Penaloza wrote:
I would like to remove rows from the following data frame (df) if
there are
only two specific elements found in the df$ch character string (I
want to
remove rows with only "0" & "D" or "0" & "d"). Alternatively, I
would like
to remove rows if the first non-zero element is "D" or "d".
ch count
1 0000000000D0000000000000000000000000000000000000 0.007368;
2 0000000000d0000000000000000000000000000000000000 0.002456;
3 000000000T00000000000000000000000000000000000000 0.007368;
4 000000000TD0000000000000000000000000000000000000 0.007368;
5 000000000T00000000000000000000000000000000000000 0.002456;
6 000000000Td0000000000000000000000000000000000000 0.002456;
7 00000000T000000000000000000000000000000000000000 0.007368;
8 00000000T0D0000000000000000000000000000000000000 0.007368;
9 00000000T000000000000000000000000000000000000000 0.002456;
10 00000000T0d0000000000000000000000000000000000000 0.002456;
I tried the following but it doesn't work if there is more than one
character per string:
df <- df[!df$ch %in% c("0","D"),]
df <- df[!df$ch %in% c("0","d"),]
You seem to be missing test cases for the second set of conditions but
this works for the first set (and might for the second):
> dat[ grepl("[^0dD]", dat$ch) & ! grepl("^0+d|^0^D", dat$ch) , ]
ch count
3 000000000T00000000000000000000000000000000000000 0.007368
4 000000000TD0000000000000000000000000000000000000 0.007368
5 000000000T00000000000000000000000000000000000000 0.002456
6 000000000Td0000000000000000000000000000000000000 0.002456
7 00000000T000000000000000000000000000000000000000 0.007368
8 00000000T0D0000000000000000000000000000000000000 0.007368
9 00000000T000000000000000000000000000000000000000 0.002456
10 00000000T0d0000000000000000000000000000000000000 0.002456
David Winsemius, MD West Hartford, CT