Get axis information from measure data — measure_axis

Extracts metadata about the axis (location dimension) of measure data, including range, spacing, direction, and inferred axis type.

Usage

measure_axis_info(x, sample = 1L)

Arguments

x: A measure_tbl, measure_list, or data frame with measure column.
sample: Integer index of sample to analyze (for measure_list). Default is 1.

Value

A list with:

min, max: Range of location values
n_points: Number of data points
spacing: Median absolute spacing between points
direction: "increasing", "decreasing", or "mixed"
regular: Logical indicating if spacing is regular (within tolerance)
axis_type: Inferred axis type (see infer_axis_type())

Examples

# NIR spectrum
spec <- new_measure_tbl(
  location = seq(1000, 2500, by = 2),
  value = rnorm(751)
)
measure_axis_info(spec)
#> $min
#> [1] 1000
#> 
#> $max
#> [1] 2500
#> 
#> $n_points
#> [1] 751
#> 
#> $spacing
#> [1] 2
#> 
#> $direction
#> [1] "increasing"
#> 
#> $regular
#> [1] TRUE
#> 
#> $axis_type
#> [1] "wavelength_nm"
#> 

# Chromatogram
chrom <- new_measure_tbl(
  location = seq(0, 30, by = 0.01),
  value = rnorm(3001)
)
measure_axis_info(chrom)
#> $min
#> [1] 0
#> 
#> $max
#> [1] 30
#> 
#> $n_points
#> [1] 3001
#> 
#> $spacing
#> [1] 0.01
#> 
#> $direction
#> [1] "increasing"
#> 
#> $regular
#> [1] TRUE
#> 
#> $axis_type
#> [1] "retention_time"
#>