Add north arrow to frames

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

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	list of ggplot2 objects, crated 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 on the function's progress are displayed (default).

Value

List of frames.

See also

frames_spatial frames_graph animate_frames

Examples

# NOT RUN {
library(moveVis)
library(move)

data("move_data", "basemap_data")
m <- align_move(move_data, res = 4, unit = "mins")

# create spatial frames using a custom NDVI base layer
r_list <- basemap_data[[1]]
r_times <- basemap_data[[2]]

# }# NOT RUN {
frames <- frames_spatial(m, r_list = r_list, r_times = r_times, r_type = "gradient",
                         fade_raster = TRUE)

# add a north arrow to frames:
frames.a <- add_northarrow(frames)
frames.a[[100]]

# or in white at another position
frames.b <- add_northarrow(frames, colour = "white", position = "bottomleft")
frames.b[[100]]
# }# NOT RUN {
# }