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Exclude Measurement Ranges

Source: R/region-operations.R
step_measure_exclude.Rd

step_measure_exclude() creates a specification of a recipe step that removes measurement points within the specified x-axis range(s).

Usage

step_measure_exclude(
  recipe,
  ranges,
  measures = NULL,
  role = NA,
  trained = FALSE,
  skip = FALSE,
  id = recipes::rand_id("measure_exclude")
)

Arguments

recipe

A recipe object. The step will be added to the sequence of operations for this recipe.

ranges

A list of numeric vectors, each of length 2 specifying ranges to exclude as c(min, max). Points with location >= min and <= max in any range are removed.

measures

An optional character vector of measure column names to process. If NULL (the default), all measure columns will be processed.

role

Not used by this step since no new variables are created.

trained

A logical to indicate if the step has been trained.

skip

A logical. Should the step be skipped when baking?

id

A character string that is unique to this step.

Value

An updated version of recipe with the new step added.

Details

This step removes measurements falling within specified ranges. This is useful for:

  • Removing solvent peaks in chromatography

  • Excluding system peaks or artifacts

  • Removing detector saturation regions

  • Removing known interference regions in spectroscopy

Multiple ranges can be excluded by providing a list of ranges. Points falling within any of the specified ranges are removed.

See also

step_measure_trim() for keeping specific ranges, step_measure_resample() for interpolating to a new grid

Other region-operations: step_measure_resample(), step_measure_trim()

Examples

library(recipes)

# Exclude specific regions (e.g., solvent peaks)
rec <- recipe(water + fat + protein ~ ., data = meats_long) |>
  update_role(id, new_role = "id") |>
  step_measure_input_long(transmittance, location = vars(channel)) |>
  step_measure_exclude(ranges = list(c(1, 5), c(95, 100))) |>
  prep()

bake(rec, new_data = NULL)
#> # A tibble: 215 × 5
#>       id water   fat protein .measures
#>    <int> <dbl> <dbl>   <dbl>    <meas>
#>  1     1  60.5  22.5    16.7  [89 × 2]
#>  2     2  46    40.1    13.5  [89 × 2]
#>  3     3  71     8.4    20.5  [89 × 2]
#>  4     4  72.8   5.9    20.7  [89 × 2]
#>  5     5  58.3  25.5    15.5  [89 × 2]
#>  6     6  44    42.7    13.7  [89 × 2]
#>  7     7  44    42.7    13.7  [89 × 2]
#>  8     8  69.3  10.6    19.3  [89 × 2]
#>  9     9  61.4  19.9    17.7  [89 × 2]
#> 10    10  61.4  19.9    17.7  [89 × 2]
#> # ℹ 205 more rows