update: Update a dataframe, functional style

In HikaGenji/fql: Functional Query Language

Usage

update(d, where = NULL, by = NULL, what = NULL)

Arguments

d	A dataframe
where	A list of expressions evaluating to booleans
by	A list of expressions defining the groups
what	A list of aggregates expressions

Value

A dataframe, same number of rows as original d object

Author(s)

JFP

See Also

select

Examples

d <- data.frame(
    date=seq(as.Date("2001-01-01"), as.Date("2001-12-01"), by="month"),
    ticker=sample(c("1 HK", "2 HK"), 12, TRUE),
    return=rnorm(12)
  )
d %>% update(by=list(ticker=expression(ticker)), what=alist(return=2)) 

HikaGenji/fql documentation built on April 12, 2021, 8:36 a.m.