Declare which column carries which axis role

The mapping decides the coordinate_system and is what spatial transformations index by, so — like the variables_* declarations — it is not reachable through set_metadata() and has its own setter, which restructures the frame too.

Usage

set_axes(data, axes)

Arguments

data

An aniframe object.

axes

Named character vector: names are axis roles, values are the columns carrying them. The roles must form a coordinate system, and every column must exist in data.

Value

data, re-declared and restructured.

Details

The direction is role to column, the same way round as get_axes() returns it and as dplyr::rename() reads, so set_axes(af, get_axes(af)) does nothing.

See also

get_axes()

Examples

df <- data.frame(time = 1:3, individual = "a", u = c(1, 2, 3), v = c(0, 1, 0))
af <- as_aniframe(df, variables_where = c("u", "v"))
#> Warning: Could not infer coordinate system from spatial variables: "u" and "v".
#> ℹ Setting coordinate system to "unknown".
#> ℹ To keep the coordinate system, say which axis each column carries with
#>   `set_axes()`.
get_metadata(af, "coordinate_system")
#> [1] unknown
#> 7 Levels: unknown cartesian_1d cartesian_2d cartesian_3d polar ... spherical

af <- set_axes(af, c(x = "u", y = "v"))
get_axes(af)
#>   x   y 
#> "u" "v" 
get_metadata(af, "coordinate_system")
#> [1] cartesian_2d
#> 7 Levels: unknown cartesian_1d cartesian_2d cartesian_3d polar ... spherical