gt_make_png {googletraffic}

Make Google Traffic PNG

Description

Make a png file of Google traffic data. The gt_load_png_as_traffic_raster() function can then be used to convert the png into a traffic raster

Usage

gt_make_png(
  location,
  height,
  width,
  zoom,
  out_filename,
  google_key,
  webshot_zoom = 1,
  webshot_delay = NULL,
  print_progress = TRUE
)

Arguments

location

Vector of latitude and longitude

height

Height (in pixels; pixel length depends on zoom)

width

Width (in pixels; pixel length depends on zoom)

zoom

Zoom level; integer from 5 to 20. For more information about how zoom levels correspond to pixel size, see here and here.

out_filename

Filename of PNG file to make

google_key

Google API key, where the Maps JavaScript API is enabled. To create a Google API key, follow these instructions.

webshot_zoom

How many pixels should be created relative to height and width values. If height and width are set to 100 and webshot_zoom is set to 2, the resulting raster will have dimensions of about ⁠200x200⁠ (default: 1).

webshot_delay

How long to wait for Google traffic layer to render. Larger height/widths require longer delay times. If NULL, the following delay time (in seconds) is used: delay = max(height,width)/200.

print_progress

Whether to print function progress (default: TRUE)

Value

Returns a PNG file showing traffic levels.

References

Markus Hilpert, Jenni A. Shearston, Jemaleddin Cole, Steven N. Chillrud, and Micaela E. Martinez. Acquisition and analysis of crowd-sourced traffic data. CoRR, abs/2105.12235, 2021.

Pavel Pokorny. Determining traffic levels in cities using google maps. In 2017 Fourth International Conference on Mathematics and Computers in Sciences and in Industry (MCSI), pages 144–147, 2017.

Examples

## Not run: 
gt_make_png(location     = c(40.712778, -74.006111),
            height       = 1000,
            width        = 1000,
            zoom         = 16,
            out_filename = "google_traffic.png",
            google_key   = "GOOGLE-KEY-HERE")

## End(Not run)