Map Center Point Calculation Rule

When writing the map JSON, someone may not understand the calculation logic of the map center point, resulting in the inability to locate the center of the map when drilling down to a clicked area. For example, the American region is not displayed at the center of the map after being clicked. The following figure shows the expected effect by the normal calculation logic.

Take the maximum and minimum values of latitude and longitude, and calculate the average to get the position of the center point.

North latitude is greater than 0; South latitude is less than 0;

East longitude is greater than 0; West longitude is less than 0;

However, if the longitude of the region crosses the east and west, the calculated center point may not be what is needed. In this case, the longitude needs to be processed into the same sign.

Example:

From the Aleutian Islands to Greenland, the longitude is approximately 170 to -20, (170-20)/2=75.

This calculation will get the center of the Americas on the Eurasian continent, which is not the desired result.

Therefore, the longitude of the Aleutian Islands is recorded as 170-360=-190, (-190-20)/2=-105.

The result longitude -105 is on the American continent.

Note:

If you use our map editor to edit, the edited result has already been processed.

In addition, for the American region is relatively large, when the corresponding zoom level at the drilling level is set to automatic, the entire region is displayed by default, and the map will not automatically zoom to the center of the American region. You are recommended to set it to 2 here.