Point Pattern Analysis

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Point Pattern Analysis
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Methods for analyzing completely censused
population data

• Entire extent of study area
• or
• Each unit of an array of contiguous sample units
  (e.g. quadrats)
• Global vs. Local

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Types of Point data

• Univariate, Bivariate, Multivariate
• 1, 2, and 3 Dimensions (x,y,z)

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Point Pattern Analysis

• Pattern may change with scale!
• Test statistic calculated from data vs. expected
  value of statistic under CSR (complete spatial
  randomness)

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Types of Point Patterns

• Random (CSR)
• Overdispersed (spaced or regular)
• Underdispersed (clumped or aggregated)

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Methods

• Distance to neighbor
• sample
• Refined Nearest Neighbor
• randomization
• Second-order point pattern analysis

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Second-order Point Pattern Analysis Ripleys K

• Used to analyse the mapped positions of events
  in the plane and assume a complete census