Density Analysis

The Big Data Distributed Analysis service provides Density Analysis and supports Simple Density Analysis and Kernel Density Analysis:

  • Simple Density Analysis: Calculates the value per unit area in the specified neighborhood shape of each point. The Calculator Method is the measurement of a point divided by the area of the specified neighborhood. Where the neighborhood of a point is superimposed, its density values are also summed. The density of each output grid is the sum of all the neighborhood density values superimposed on the grid. The unit of the Result Raster value is the reciprocal of the square of the original Dataset unit, that is, if the original Dataset unit is meter, the unit of the Result Raster value is per square meter.
  • Kernel Density Analysis: used to calculate the unit density of point and line feature measurement values within the specified neighborhood. Simply speaking, it can intuitively reflect the distribution of discrete measurements in a continuous region. The result is a smooth surface with a large intermediate value and a small perimeter value, and the grid value is the unit density, which drops to 0 at the neighborhood boundary. Kernel Density Analysis can be used to calculate population density, building density, obtain crime reports, monitor population density in tourist areas, analyze the operation of chain stores, etc.

Application scenario

  • Analyze the density of terrorist attacks in various regions of the world.
  • Analyze the traffic flow according to the vehicle GPS positioning data.

Function entrance

  • Online tab-> Analysis group-> Density Analysis.

Operating instructions

  1. IServerServer Address: Login iServerServer Address and account through drop-down options. For details, see the Data entry page.
  2. Source Data: Used to set the Dataset for summary. Only Line Dataset and Region Dataset are supported. Click the Drop-down Button and select. The drop-down options will automatically filter the Source Dataset that meets the analysis requirements. For details, see the Data entry page.
  3. Analysis Settings：
    • Analysis Method: Simple Density Analysis and Kernel Density Analysis are supported. Click the Drop-down Button to select.
    • Mesh Face Type: Specifies whether the mesh unit is a Quadrilateral Mesh or a Hexagonal Mesh. Required parameters.
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    • Weight Field: Specifies the Field set where the weight values of the points to be analyzed are located. Format: col7, col8. Optional parameters. Note: Multiple Field Indexes representing weights can be passed, separated by commas, which is equivalent to multiple operations on the points to be analyzed, each of which corresponds to a different weight value. If The parameter is empty, the weight of the point is 1. A weight value of 1 is automatically analyzed whether the value is set or not. The result is reflected in the property sheet field of the Result Dataset.
    • Analysis Bounds: The point data outside the analysis area does not participate in the calculation, and the default value is the full range of Input Data:.
    • Mesh Size: For Quadrilateral Mesh, the edge length of the mesh. For Hexagonal Mesh, the distance from the vertex of the hexagon to the center point. The default value is 50.
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    • Grid size unit: The units provided are: meter, kilometer, yard, mile and foot. The default value is meter.
    • Search Radius: The search radius used to calculate the density. The default is 300.
    • Search radius length unit: The units provided are meter, kilometer, yard, mile and foot. The default value is meter.
    • Area unit: Denominator unit of density. Optional values: square meters, km \ u00B2, hectares, acres, acres, ft \ u00B2, square yards, square miles. The default value is square meters.
  4. Thematic parameters
    • Segmentation Mode: Set the segmentation mode of the thematic map. Equidistant Interval, Logarithmic Interval, Quantile Interval, Square Root Interval and Standard Deviation Interval are provided.
    • Number of segments: Set the number of segments of the thematic map.
    • Color Gradient Mode: Set the color gradient mode of the thematic map. Green Orange Purple Gradient, Green Orange Gradient, Rainbow Color, Spectral Gradient and Terrain Gradient are provided.
  5. Analyst Result: Execute Analysis after setting the above parameters. The Analyst Result will be automatically opened in Map, and the Save path of Result Data will also be opened in Output Window. Get the Result Dataset from this path. Note: If the user directly opens the data of the generation result path, he will be prompted that the data cannot be opened because the data is occupied based on the analysis of the iSever service. It is recommended that the user copy the data to another path and open the data for editing.

    The following chart shows the Kernel Density Analysis Result of the transaction amount in the United States:

Related topics

Environment configuration

Data Preparation