Using regexp to select rows in R dataframe
dataframe, r, regex
Solution
subset(dat, grepl("ADN", bName) & pName == "2011-02-10_R2" )
Note `&` (and not `&&` which is not vectorized) and that `==` (and not `=` which is assignment).
Note that you could have used:
dat[ with(dat, grepl("ADN", bName) & pName == "2011-02-10_R2" ) , ]
... and that might be preferable when used inside functions, however, that will return `NA` values for any lines where `dat$pName` is `NA`. That defect (which some regard as a feature) could be removed by the addition of `& !is.na(dat$pName)` to the logical expression.
Problem
I'm trying to select rows in a dataframe where the string contained in a column matches either a regular expression or a substring: dataframe: ``` aName bName pName call alleles logRatio strength AX-11086564 F08_ADN103 2011-02-10_R10 AB CG 0.363371 10.184215 AX-11086564 A01_CD1919 2011-02-24_R11 BB GG -1.352707 9.54909 AX-11086564 B05_CD2920 2011-01-27_R6 AB CG -0.183802 9.766334 AX-11086564 D04_CD5950 2011-02-09_R9 AB CG 0.162586 10.165051 AX-11086564 D07_CD6025 2011-02-10_R10 AB CG -0.397097 9.940238 AX-11086564 B05_CD3630 2011-02-02_R7 AA CC 2.349906 9.153076 AX-11086564 D04_ADN103 2011-02-10_R2 BB GG -1.898088 9.872966 AX-11086564 A01_CD2588 2011-01-27_R5 BB GG -1.208094 9.239801 ``` For example, I want a dataframe containing only rows that contain `ADN` in column `bName`. Secondarily, I would like all rows that contain `ADN` in column `bName` and that match `2011-02-10_R2` in column `pName`. I tried using functions `grep()`, `agrep()` and more but without success...