fast_filter_variables {dataPreparation} R Documentation

## Filtering useless variables

### Description

Delete columns that are constant or in double in your data_set set.

### Usage

fast_filter_variables(
data_set,
level = 3,
keep_cols = NULL,
verbose = TRUE,
...
)


### Arguments

 data_set Matrix, data.frame or data.table level which columns do you want to filter (1 = constant, 2 = constant and doubles, 3 = constant doubles and bijections, 4 = constant doubles bijections and included)(numeric, default to 3) keep_cols List of columns not to drop (list of character, default to NULL) verbose Should the algorithm talk (logical or 1 or 2, default to TRUE) ... optional parameters to be passed to the function when called from another function

### Details

verbose can be set to 2 have full details from which functions, otherwise they don't log. (verbose = 1 is equivalent to verbose = TRUE).

### Value

The same data_set but with fewer columns. Columns that are constant, in double, or bijection of another have been deleted.

### Examples

# First let's build a data.frame with 3 columns: a constant column, and a column in double
df <- data.frame(col1 = 1, col2 = rnorm(1e6), col3 = sample(c(1, 2), 1e6, replace = TRUE))
df$col4 <- df$col2
df$col5[df$col3 == 1] = "a"
df$col5[df$col3 == 2] = "b" # Same info than in col1 but with a for 1 and b for 2