Skip to contents

Extract slices from n-dimensional measurement

Source: R/nd_reduce.R
measure_slice.Rd

Fixes one or more dimensions at specific coordinate values or ranges, returning a lower-dimensional result.

Usage

measure_slice(x, ..., drop = TRUE)

Arguments

x

A measure_nd_tbl or measure_nd_list object.

...

Named arguments specifying slice conditions. Names should be dimension numbers (e.g., dim_1 = 5) or dimension names if set (e.g., time = 5). Values can be:

  • A single value: exact match

  • A numeric vector: match any of these values

  • A function: applied to coordinates, should return logical

drop

Logical. If TRUE (default), dimensions with a single value are dropped from the result. If FALSE, they are retained.

Value

A measure_tbl, measure_nd_tbl, measure_list, or measure_nd_list depending on the number of remaining dimensions.

Examples

# Create a 3D measurement (2 x 3 x 4)
m3d <- new_measure_nd_tbl(
  location_1 = rep(1:2, each = 12),
  location_2 = rep(rep(1:3, each = 4), 2),
  location_3 = rep(1:4, 6),
  value = 1:24,
  dim_names = c("sample", "time", "wavelength")
)

# Extract slice at sample = 1
slice_2d <- measure_slice(m3d, dim_1 = 1)
measure_ndim(slice_2d)  # 2D
#> [1] 2

# Extract at specific time points
slice_subset <- measure_slice(m3d, dim_2 = c(1, 3))

# Use dimension names
slice_wl <- measure_slice(m3d, wavelength = 2)