Build the model

To perform density clustering analysis on urban POI data, it is necessary to read the analyzed data, then analyze the read data, and then save the resulting data obtained from the analysis.

The model consists of three tools: reading vector data, density cluster analysis, and saving vector data, as shown in the figure:

1. Add tools

Processing automation tools can be added in the following ways:

• Enter the processing modeler page, select the tool you want to use to build the model in the list of processing automation tools on the left, drag it to the canvas in the middle of the page, and the tool and its nodes will be displayed on the canvas.

• Query the desired tool through the search box above the list of processing automation tools, and then drag it to the canvas for modeling.

• The tools added to the canvas support frame selection of multiple tools, copy (Ctrl+C) and paste (Ctrl+V) in the current canvas and across canvases.

2. Mobile tools

Drag-and-drop process automation tools into the canvas support movement and manipulation:

• Tool overall movement: use the left mouse button to select the function node of the tool to move.

3. Connection tool

A model usually needs to be composed of multiple processing automation tools, and connections need to be established between the tools. The main operations for drawing connections are:

1. Move the cursor to the connection point of the output node of the front tool, and the connection point will be highlighted.

2. Hold down the left mouse button and move the cursor to the connection point of the input node of the tool to be connected. After the connection point is highlighted, release the mouse, and the connection line is drawn successfully. In order to ensure the normal operation of the model, it is necessary to ensure that the output parameters of the previous nodes are the same as the input parameters of the subsequent nodes.

3. After clicking to select a tool or connection line, select Delete in the right-click menu, or use the Delete key on the keyboard to delete it.

4. If the tool is deleted by mistake, there is no need to drag and drop again. All operations on the modeling canvas support shortcut keys to undo (Ctrl+Z) and restore (Ctrl+Y).

4. Rename Tool

When the model contains multiple tools with the same name or the tool name does not match the usage scenario, you can click the left mouse button to select the tool node, and select "Rename" in the right-click menu to rename the tool.

5. Simplified display tools

When there are too many tool parameters or too many tools, the visual modeling page will appear cluttered. You can right-click the blank area of the canvas and select the "Collapse All" button to collapse the tool parameters. The folded tools also support movement.

At the same time, you can also select "Horizontal Auto Layout" or "Vertical Auto Layout" in the menu on the right side of the canvas to neatly layout the canvas. Through these operations, the display of visual modeling can be optimized.

6. Add annotation

When the model is complex, the business process is not easy to understand. You can add annotations to the model elements to improve the legibility of the model. To add annotations to the model, just right-click on the blank area of the canvas and select "Create Annotation". In addition, you can also add a label to a single tool node, click the left mouse button to select the tool node, and select "Create Label" in the right-click menu. The label added to the tool node can be moved together when the tool node is moved.

In addition, the xml template for visual modeling can also be imported into the canvas for modeling through File->Import Model.