367 reputation
312
bio website ailin.phychembio.com
location Hong Kong
age
visits member for 2 years, 10 months
seen 7 hours ago

Oct
1
accepted How to get the tripoint of three or more polygons in PostGIS?
Sep
29
comment How to get the tripoint of three or more polygons in PostGIS?
For the red polygon, the point that touches the tripoint is not the vertex. ST_DumpPoints is not able to return that point. Am I correct?
Sep
29
comment How to get the tripoint of three or more polygons in PostGIS?
Thanks for your solution. It does not solve all the case. Such as tripoint at the star position of these polygons. imgur.com/6weN9dz
Sep
29
asked How to get the tripoint of three or more polygons in PostGIS?
Sep
18
awarded  Notable Question
Sep
17
accepted How to get the regional maximum or minimum of raster data by using PostGIS?
Sep
15
comment How to get the regional maximum or minimum of raster data by using PostGIS?
yes. I am interested in local max or min value. If it is global max and min, I can only get 1 max and 1 min. It is not what I want.
Sep
15
comment How to get the regional maximum or minimum of raster data by using PostGIS?
Oh, I am sorry that you misunderstood my question. What I mean is that, by using raw raster data, find out the min and max of a region. There are no character H and L in the image. But thanks for your effort!
Sep
13
revised How to get the regional maximum or minimum of raster data by using PostGIS?
edited title
Sep
13
asked How to get the regional maximum or minimum of raster data by using PostGIS?
Aug
12
awarded  Caucus
Aug
8
comment How to calculate bus route transfer by using pgrouting?
Excuse me, does multi-modal routing mean different transport means? If so, it is one of the case.
Aug
7
asked How to calculate bus route transfer by using pgrouting?
Jul
17
awarded  Notable Question
Jul
2
awarded  Curious
May
24
accepted Possible to store 3D features such as dome into geospatial database?
May
23
comment Possible to store 3D features such as dome into geospatial database?
What is the difference of TIN and POLYHEDRALSURFACE in terms of their usage?
May
22
comment Possible to store 3D features such as dome into geospatial database?
I have just had researched on it, how about TIN and POLYHEDRALSURFACE?
May
22
comment Possible to store 3D features such as dome into geospatial database?
It is not necessary be a true curve, but the way of describing such shape.
May
22
asked Possible to store 3D features such as dome into geospatial database?