Get metadata

The metadata is stored as a category tree (see list_default_metadata()), but lookup stays flat: a field is found by its own name wherever it lives, and a category name returns the whole category. The variables category is the exception — its slots are reached through the *_variables_*() accessors, get_index() and get_axes(), not by flat name.

Usage

get_metadata(data, fields = NULL)

Arguments

data

An aniframe or anievent object.

fields

Field or category names. A field the object does not carry gives NULL — an anievent() has no space category, so its spatial fields read as absent rather than as neutral values. A name that is not a metadata field at all is an error.

Value

The metadata associated with the object.

Examples

af <- example_anipoint(n_obs = 3, n_individuals = 1, n_keypoints = 1)
names(get_metadata(af))
#> [1] "spec_version" "recording"    "time"         "space"        "variables"   
#> [6] "structure"   

# A single field can be pulled out by name, wherever it lives
get_metadata(af, 'sampling_rate')
#> [1] NA

# A category name returns the whole category
names(get_metadata(af, 'space'))
#> [1] "coordinate_system" "reference_frame"   "handedness"       
#> [4] "axis_directions"   "axis_extents"      "unit_space"       
#> [7] "unit_angle"        "euler_sequence"    "euler_intrinsic"