shipunov (version 1.17.1)

Pull: Select rows from data frame

Description

Selects rows from data frame basing on the evaluation of the second argument

Usage

Pull(df, ...)

Value

Data frame

Arguments

df

Data frame to select from

...

Arguments to with(df, ...)

Author

Alexey Shipunov

Details

If the first argument is not a data frame, function will stop with an error.

Pull() is similar to subset() (but is much simpler and allows non-logical values) and to dplyr::filter() function.

Please avoid using Pull() in non-ineractive mode.

Examples

`[`(trees, 3, 1) # ... so square bracket is a command
## arguments of `[` are independent; this is why square bracket does not "catch" the context:
trees[trees$Girth < 11 & trees$Height == 65, ] # boring and long
trees[trees$Girth < 11 & sample(0:1, nrow(trees), replace=TRUE), ] # yes, boring, long but flexible
trees[with(trees, Girth < 11 & Height == 65), ] # less boring but still long
## it would be nice to avoid typing "trees" twice:
Pull(trees, Girth < 11 & Height == 65) # shorter
Pull(trees, Girth < 11 & sample(0:1, nrow(trees), replace=TRUE)) # flexibility is still here
Pull(trees, Girth < 11 & sample(0:1, nrow(trees),
 replace=TRUE))$Height # if you want also select columns
Pull(trees, grep(81, Height)) # select not only by TRUE/FALSE but also by row index