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QGIS (In class (Spatial statistics (raster dataset (nearest neighbor),…

- - - - nearest neighbor
    - - clusters and outliers
- - - - vector data
        
        lines
        
        points
        
        CRS:Coordinate Reference System
        
        polygon
        
        enclosed areas
        
        share boundaries
        
        Topology: spatial relationship (network analysis)
        
        common problems
        
        undershoots: lines does not meet
        
        silvers: polygons does not meet
        
        stored in coordinates
      - raster data
        
        stored as a grid of values
        
        remote sensing
        
        aerial photography
        
        satellite imagery
        
        compute raster data
        
        create from
        
        good for continuously changing value
        
        georeferencing
        from map to place
    - - Attributes:
        text | number to describe feature
        
        symbology
        
        Graduated color: discrete
        
        Continuous color
        
        Table:
        numerical, string and date
        
        row:record
        
        column:field
      - Geometry:
    - - files
        
        .dbf: attributes
        
        .shx: index
        
        .shp: geometry
      - creating a Shapefiles
        
        Heads-up digitizing :
        raster photo
        
        Digitising table (puck):
        device + paper map
    - - Vector spatial analysis | geoprocessing
        
        Buffers
        
        Difference
        
        Union
        
        Intersection
        
        Symmetrical difference
      - spatial Analysis | Interpolation 插值法
        
        digital elevation
        
        Triangulated Irregular Network (TIN) ：避免狭长三角形
        
        Inverse Distance Weighted (IDW) ：距离越长权重越小
        
        for a continuous map