In QuayAu/fxtract: Feature Extraction from Grouped Data

Use case:

• Features have been added (or have already been calculated).
• We want to edit a feature function.

All features have been calculated:

xtractor$results

Write Updated Feature Functions

Let's say we want to edit our features to use the robust measures median() and mad().

First we need to write the functions:

fun1_robust = function(data) {
  c(median_sepal_length = median(data$Sepal.Length),
    mad_sepal_length = mad(data$Sepal.Length))
}

fun2_robust = function(data) {
  c(median_petal_length = median(data$Petal.Length),
    mad_petal_length = mad(data$Petal.Length))
}

Delete Old Feature Functions

xtractor$remove_feature(fun1)

This deletes all calculated features corresponding to fun1.

It's also possible to pass a character string:

xtractor$remove_feature("fun2")

Add New Feature Functions

All there is left to do is to add the new feature functions and to execute the calculation process:

xtractor$add_feature(fun1_robust)
xtractor$add_feature(fun2_robust)

xtractor$calc_features()
xtractor$results

unlink("fxtract_files", recursive = TRUE)

QuayAu/fxtract documentation built on June 8, 2020, 10:26 p.m.