StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
text
Body
copied!<p>Yes, it is. I've had a similar problem, so I've written it up. Like this:</p> <pre><code>use Math::Trig; sub getTileNumber { my ($lat,$lon,$zoom) = @_; my $xtile = int( ($lon+180)/360 * 2**$zoom ) ; my $ytile = int( (1 - log(tan(deg2rad($lat)) + sec(deg2rad($lat)))/pi)/2 * 2**$zoom ) ; return ($xtile, $ytile); } sub getLonLat { my ($xtile, $ytile, $zoom) = @_; my $n = 2 ** $zoom; my $lon_deg = $xtile / $n * 360.0 - 180.0; my $lat_deg = rad2deg(atan(sinh(pi * (1 - 2 * $ytile / $n)))); return ($lon_deg, $lat_deg); } # convert from permalink OSM format like: # http://www.openstreetmap.org/?lat=43.731049999999996&lon=15.79375&zoom=13&layers=M # to OSM "Export" iframe embedded bbox format like: # http://www.openstreetmap.org/export/embed.html?bbox=15.7444,43.708,15.8431,43.7541&layer=mapnik sub LonLat_to_bbox { my ($lat, $lon, $zoom) = @_; my $width = 425; my $height = 350; # note: must modify this to match your embed map width/height in pixels my $tile_size = 256; my ($xtile, $ytile) = getTileNumber ($lat, $lon, $zoom); my $xtile_s = ($xtile * $tile_size - $width/2) / $tile_size; my $ytile_s = ($ytile * $tile_size - $height/2) / $tile_size; my $xtile_e = ($xtile * $tile_size + $width/2) / $tile_size; my $ytile_e = ($ytile * $tile_size + $height/2) / $tile_size; my ($lon_s, $lat_s) = getLonLat($xtile_s, $ytile_s, $zoom); my ($lon_e, $lat_e) = getLonLat($xtile_e, $ytile_e, $zoom); my $bbox = "$lon_s,$lat_s,$lon_e,$lat_e"; return $bbox; } </code></pre> <p>I've also added this info to <a href="http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#Lon..2Flat._to_bbox" rel="nofollow">OSM wiki</a>, so it will be easier to find in the future...</p>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload