JavaScript-the database holds a lot of plots, each area of the parcel is determined by the latitude and longitude of four vertices, I know a point of latitude and longitude, how to determine the location belongs to which land?

Ask you to give a thought ~

Reply content:

Ask you to give a thought ~

Correct the demand, PO Master's demand is "geo-fence"

Solution:
Postgis+postgresql
Elasticsearch/solr

I'm afraid I can't do it by MySQL.
or redesign the library.

place_id	name
1	Block 1

ID	place_id	lat	LNG
1	1	1.1111	1.1111
2	1	1.1111	1.1111
3	1	1.1111	1.1111
4	1	1.1111	1.1111

Reference: http://www.cnblogs.com/LBSer/...

You this seems to be a purely mathematical problem, to say the idea, you can use four small triangles t1-t4 the quadrilateral complement into a rectangular r, now inconvenient to draw, you imagine. And then judge to give the point P

p 在 R 内   &&   p 不在 {T1-T4} 内

Define a Point object: P[x,y], X is latitude, y is longitude
Area of the parcel four vertices are: a[x,y], b[x,y], c[x,y], D[x,y]
Known points are: Ptr[x,y]

UH ~ ~
You should give me a few samples.
Otherwise, also to you science and geography knowledge, it is too wordy ~

Using the MySQL space function and operation, save directly save a polygon area, judge the time using the St_contains function

Using Point, St_astext, POLYGON, st_x, st_y, st_distance, these are much better than direct-saving jingwei.

Http://dev.mysql.com/doc/refm ...

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