bbox_to_tile_grid {slippymath}

bbox_to_tile_grid

Description

Bounding box to tile grid

Usage

bbox_to_tile_grid(bbox, zoom = NULL, max_tiles = NULL)

Arguments

bbox

the bounding box to fit onto a grid of tiles. Must be either a 'bbox' object created with sf::st_bbox or a vector of length 4 with names: 'xmin', 'xmax', 'ymin', 'ymax'.

zoom

Optional. The desired zoom level.

max_tiles

Optional. The maximum number of tiles the grid may occupy.

Details

Calculate a slippy map tile grid that will fit a supplied bounding box.

The grid is returned as part of a tile_grid object that contains a data.frame of x,y tile numbers and zoom level.

The tile grid can be calculated for a given zoom level or for the deepest zoom that ensures the number of tiles is less than or equal to 'max_tiles'.

If 'zoom' and 'max_tiles' are supplied together, then the max is still enforced and the function will fail if more tiles are required for the given zoom.

Value

a 'tile_grid' object containing 'tiles' and 'zoom'

Examples

tibrogargan<- c(xmin = 152.938485, ymin = -26.93345, xmax = 152.956467, 
               ymax = -26.921463)

## Get a grid of the minimum number of tiles for a given zoom.
bbox_to_tile_grid(tibrogargan, zoom = 15)

## get a grid of at most 12 tiles, choosing the most detailed zoom possible.
bbox_to_tile_grid(tibrogargan, max_tiles = 12)