crankshaft/doc/15_tinmap.md

37 lines
1.3 KiB
Markdown
Raw Normal View History

2016-08-10 00:09:19 +08:00
## TINMAP function
Generates a fake contour map, in the form of a TIN map, from a set of scattered points.Depends on **CDB_Densify**.
2016-08-30 19:44:58 +08:00
Its iterative nature lets the user smooth the final result as much as desired, but with a exponential time cost increase.
2016-08-10 00:09:19 +08:00
### CDB_TINmap(geomin geometry[], colin numeric[], iterations integer)
#### Arguments
| Name | Type | Description |
|------|------|-------------|
| geomin | geometry[] | Array of points geometries |
| colin | numeric[] | Array of points' values |
| iterations | integer | Number of iterations |
### Returns
Returns a table object
| Name | Type | Description |
|------|------|-------------|
| geomout | geometry | Geometries of new dataset of polygons|
| colout | numeric | Values of each cell|
#### Example Usage
```sql
with data as (
select
ARRAY[7.0,8.0,1.0,2.0,3.0,5.0,6.0,4.0] as colin,
ARRAY[ST_GeomFromText('POINT(2.1744 41.4036)'),ST_GeomFromText('POINT(2.1228 41.3809)'),ST_GeomFromText('POINT(2.1511 41.3742)'),ST_GeomFromText('POINT(2.1528 41.4136)'),ST_GeomFromText('POINT(2.165 41.3917)'),ST_GeomFromText('POINT(2.1498 41.3713)'),ST_GeomFromText('POINT(2.1533 41.3683)'),ST_GeomFromText('POINT(2.131386 41.413998)')] as geomin
)
select CDB_TINmap(geomin, colin, 2) from data;
```