Add north arrow to frames

This function adds a north arrow to frames created with frames_spatial.

Usage

add_northarrow(
  frames,
  height = 0.05,
  position = "bottomright",
  x = NULL,
  y = NULL,
  colour = "black",
  size = 1,
  label_text = "N",
  label_margin = 0.4,
  label_size = 5,
  verbose = TRUE
)

Arguments

frames

an object of class moveVis created with frames_spatial.

height

numeric, height of the north arrow in a range from 0 to 1 as the proportion of the overall height of the frame map.

position

character, position of the north arrow on the map. Either "bottomleft", "upperleft", "upperright", "bottomright". Ignored, if x and y are set.

x

numeric, position of the bottom left corner of the north arrow on the x axis. If not set, position is used to calculate the position of the north arrow.

y

numeric, position of the bottom left corner of the north arrow on the y axis. If not set, position is used to calculate the position of the north arrow.

colour

character, colour.

size

numeric, arrow size.

label_text

character, text below the north arrow.

label_margin

numeric, margin between label and north arrow as a proportion of the size of the north arrow.

label_size

numeric, label font size.

verbose

logical, if TRUE, messages and progress information are displayed on the console (default).

Value

A frames object of class moveVis.

Details

For adding more sophisticated map features, I recommend ggspatial.

See also

frames_spatial frames_graph animate_frames

Author

Jakob Schwalb-Willmann

Examples

library(moveVis)
library(move2)
library(terra)

data("move_data", package = "moveVis")
r <- readRDS(example_data(file = "raster_NDVI.rds"))

# align movement
m <- align_move(move_data, res = units::set_units(4, "min"))
#> Temporal resolution of 4 [min] is used to align trajectories.

# create frames and add northarrow
frames <- frames_spatial(m, r, r_type = "gradient", fade_raster = TRUE) %>% 
  add_northarrow()
#> Processing input data...
#> Approximated animation duration: ≈ 7.52s at 25 fps using 188 frames
#> CRS (geodetic):   WGS 84
#> Assigning raster maps to frames...
frames[[100]]


# or in white at another position
frames <- frames_spatial(m, r, r_type = "gradient", fade_raster = TRUE) %>% 
  add_northarrow(colour = "white", position = "bottomleft")
#> Processing input data...
#> Approximated animation duration: ≈ 7.52s at 25 fps using 188 frames
#> CRS (geodetic):   WGS 84
#> Assigning raster maps to frames...
frames[[100]]