do_repeat: Repeats the same transformations on a specified set of variables/values

Description

Repeats the same transformations on a specified set of variables/values

Usage

do_repeat(data, ...)
.do_repeat(...)

Arguments

data

data.frame/list. If data is list then do_repeat will be applied to each element of the list.

...

stand-in name(s) followed by equals sign and a vector of replacement variables or values. Characters considered as variables names, all other types considered as is. Last argument should be expression in curly brackets which will be evaluated in the scope of data.frame data. See examples.

Value

transformed data.frame data

Details

There is a special constant .N which equals to number of cases in data for usage in expression inside do_repeat. Also there is a variable .item_num which is equal to the current iteration number.

Examples

Run this code

# NOT RUN {
data(iris)
scaled_iris = do_repeat(iris, 
                        i = qc(Sepal.Length, Sepal.Width, Petal.Length, Petal.Width), 
                        {
                            i = scale(i)
                        })
head(scaled_iris)

# several stand-in names
old_names = qc(Sepal.Length, Sepal.Width, Petal.Length, Petal.Width)
new_names = paste0("scaled_", old_names)
scaled_iris = do_repeat(iris, 
                        orig = old_names, 
                        scaled = new_names, 
                        {
                            scaled = scale(orig)
                        })
head(scaled_iris)

# numerics
new_df = data.frame(id = 1:20)
new_df = do_repeat(new_df, 
                   item = qc(i1, i2, i3), 
                   value = c(1, 2, 3), 
                   {
                       item = value
                   })
head(new_df)

# the same result with internal variable '.item_num'
new_df = data.frame(id = 1:20)
new_df = do_repeat(new_df, 
                   item = qc(i1, i2, i3),
                   {
                       item = .item_num
                   })
head(new_df)

# functions
set.seed(123)
new_df = data.frame(id = 1:20)
new_df = do_repeat(new_df, 
                   item = qc(i1, i2, i3), 
                   fun = c("rnorm", "runif", "rexp"), 
                   {
                       item = fun(.N)
                   })
head(new_df)


# }