Algorithmic techniques

Expression fast calculations: Algorithmic techniques

algorithmic techniques

• Sampling and Scaling: used to speed-up Discrete Allocation
• Convolution by Fast Fourier Transformation (FFT) for Potential calculations.
  • A convolution performance comparison between ESRI’s ArcGIS (focal sum, 26 hrs) and the GeoDMS (potential, 2 minutes) is done for the GIS performance contest of the Spatial Analysis dept of the Vrije Universiteit of Amsterdam. The contest provided a 1 km world wide grid and a 50 km kernel.
• Use of spatial indices :
  • QuadTrees in geometric algorithms and
  • TileGrids for visualisation.
• Development of faster algorithms for specific operations: Fisher’s Natural Breaks Classification complexity proof, Discrete Allocation