41 lines
846 B
Markdown
41 lines
846 B
Markdown
## Gravity Model
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### CDB_Gravity()
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The Gravity Model is derived from newtons law of gravity and is used to estimate the degree of interaction between two places
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#### Arguments
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| Name | Type | Description |
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|------|------|-------------|
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| t_id | bigint[] | |
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| t_geom | geometry[] | |
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| t_weight | numeric[] | |
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| s_id | bigint[] | |
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| s_geom | geometry[] | |
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| s_pop | numeric[] | |
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| target | bigint | |
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| radius | integer | |
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| minval | numeric | |
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#### Returns
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| Column Name | Type | Description |
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|-------------|------|-------------|
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| the_geom | Numeric | |
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| source_id | bigint | |
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| target_id | bigint | |
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| dist | Numeric | |
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| n | Numeric | |
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| hpop | NUMERIC | |
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#### Example Usage
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```sql
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SELECT CDB_GRAVITY ();
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```
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