Extract measurements from sampled_data.frame and polygons

Extract measurements from sampled_data.frame and polygons

subsampling_trait_extraction(
  x,
  polygons,
  sample_index,
  trait.subset = NULL,
  stom.val = 85,
  subs.val = 170,
  pave.val = 255
)

Arguments

x

List of the form output by extract_epidermal_traits() (see documentation of that function for details)

polygons

sf object containing the cell polygons that were used to generate sample_index

sample_index

Numeric vector of cells to be measured.

trait.subset

Character. Specific traits to measure. Defaults to NULL (all traits measured).

stom.val

Numeric. Value of stomata. Defaults to 85.

subs.val

Numeric. Value of subsidiary cells. Defaults to 170.

pave.val

Numeric. Value of pavement cells. Defaults to 255.

Value

A vector with whole-image values.

Details

This function is designed to be used when the image has already been processed and all cells have already been measured (e.g. when evaluating sampling effort). For unmeasured images, see extract_epidermal_traits().