| | Source | Destination |
| ---------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **WKT** | `POINT(-77.03511810000001 38.89876175)` | `POINT(-77.00585175000001 38.87462997)` |
| **Location** **Description** | The corner of Madison Place Northwest and Pennsylvania Avenue Northwest | The corner of N Street Southeast and Southeast 1st street |
| **WMS** **Location** |
|
|
| | Source | Destination | Destination | Destination | Destination |
| ---------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **WKT** | `POINT(-77.00576019 38.89677811)` | `POINT(-77.03517151 38.8898201)` | `POINT(-77.03626251 38.88068008)` | `POINT(-77.04974365 38.89020157)` | `POINT(-77.01207733 38.89072037)` |
| **Location** **Description** | Union Station | Near the Washington Monument | Near the Jefferson Memorial | Near the Lincoln Memorial | Near Capitol Hill |
| **WMS** **Location** |
|
|
|
|
|
*Weights* in this graph, as mentioned previously, are an abstract cost
(distance, time, etc.) for traveling any roadway or footpath in the Washington,
D.C., area. *Weights* are particularly important when solving a graph. There are
two solver types presented in the tutorial below:
* `shortest_path` -- Find the shortest path between two points on a graph
* `multiple_routing` -- Find the quickest route between a source point and
many destination points; also known as traveling salesman
Because there are no explicit *nodes* in the tutorial graph, source and
destination point(s) must be selected from any of the *edges* comprising the
Washington, D.C., road network. Otherwise, the graph will not be able to
traverse to the point and will result in a null solution.
## Tutorial via GUI
This tutorial is designed to be used with the *GAdmin* graph GUI.
To access this GUI:
1. Navigate to *GAdmin* and login (`http://localhost:8080/`)
2. In the top menu, click **Data --> Graphs**
All available graph actions are in the menu on the left side of *GAdmin*.
### Create Schema
Before starting with graph creation, a schema, `graph_gui`, will be
created to contain the tables supporting graph creation & solving.
To create the schema:
1. From the graph GUI, in the left menu, click **Tables**.
2. On the **Schemas** page, click **+ Schema** to add a schema.
3. Input `graph_gui` for the **Schema Name** and click
**Add**.
### Create Graph
One graph is used for both graph solving examples in the tutorial:
`dc_shape_graph`, a graph based on the aforementioned `dc_shape` dataset.
To create the graph:
1. Return to the graph GUI, and in the left menu, click **+ Create**
under **Graphs**.
2. Input `graph_gui.dc_shape_graph` for the **Graph Name**.
3. Select **True** under **Directed Graph**. The graph is
[directed](/content/graph_solver/network_graph_solver#directed-graphs) because the roads in the dataset have
directionality (one-way and two-way roads)
4. Skip selecting a configuration for **Nodes**. The graph will have no
explicitly defined *nodes* because the example relies on implicit *nodes*
attached to the defined *edges*.
5. For **Edges**:
1. Click the configuration drop-down menu and select
`EDGE_WKTLINE, EDGE_DIRECTION`.
2. Click **Add**.
3. Input `graph.dc_shape.shape` next to
**as EDGE\_WKTLINE**. The *edges* will be derived from the WKT
LINESTRINGs in this column.
4. Input `graph.dc_shape.direction` next to
**as EDGE\_DIRECTION**. The *edges'* directionality will be derived
from the integers in this column.
6. For **Weights**:
1. Click the configuration drop-down menu and select
`WEIGHTS_EDGE_WKTLINE, WEIGHTS_EDGE_DIRECTION, WEIGHTS_VALUE_SPECIFIED`.
2. Click **Add**.
3. Input `graph.dc_shape.shape` next to
**as WEIGHTS\_EDGE\_WKTLINE**. This will match the *weights* to the
*edges* by using the same WKTs.
4. Input `graph.dc_shape.direction` next to
**as WEIGHTS\_EDGE\_DIRECTION**. This will match the *weights* to
the *edges'* directionality.
5. Input `ST_LENGTH(graph.dc_shape.shape,1)/(ST_NPOINTS(graph.dc_shape.shape)-1)`
next to **as WEIGHTS\_VALUESPECIFIED**. The *weights* will be
represented as distance, which is calculated as the length of the entire
`shape` column's LINESTRING (in meters) divided by the number of points
in the LINESTRING minus 1
7. Skip selecting a configuration for **Restrictions**. The graph will
have no restrictions on any *nodes* or *edges*.
8. For **Options**:
1. Set the **Merge Tolerance** to `0.00001`. This will merge nodes
that are within one meter of each other.
2. Set **Recreate** to **True**. This will recreate the graph
if it already exists.
3. Set **Enable Graph Draw** to **True** and input
`graph_gui.dc_shape_graph_table` for the
**Graph Table**. This will create a table containing the graph
information in addition to creating the graph.
9. Click **Create New Graph**. A WMS window will open, displaying the
graph.
### Solve the Graph (Shortest Path)
### Solve the Graph (Multiple Routing)
The following scenario has been designed to illustrate a multiple routing
solution:
You're currently taking the subway to Union Station to visit Washington D.C.
for the day. You would like to see some of the most iconic monuments and
buildings in Washington, D.C. before returning back to Union Station. Starting
from Union Station, what's the quickest route between each stop before returning
back to Union Station?
