Package microsim.space

Class DoubleDiffuseSpace

  • All Implemented Interfaces:
    EventListener
    public class DoubleDiffuseSpace
extends DoubleSpace
implements EventListener
    Discrete 2nd order approximation of 2d diffusion with evaporation. Essentialy a java implementation of Diffuse2d in the Swarm simulation toolkit. Toroidal in shape and works with number values. This space simulates concurency through the use of a read and write matrix. Any writes to the space, write to the write matrix, and any reads to the read matrix. The diffuse() method then diffuses the write matrix and copies the new values into the read matrix.

    For an example of a DblDiffuseTorusGrid space see the heatBugs example. See diffuse for a brief explanation of the diffusion algorithm. Note that this space doesn't seem to work correctly when run with hotspot 1.01

    Version:
    $Revision: 1.2 $ $Date: 2004/08/11 09:05:30 $
    Author:
    Nick Collier

    • Constructor Detail

      • DoubleDiffuseSpace

        public DoubleDiffuseSpace​(int xSize,
                          int ySize)
        Constructs a DblDiffuseTorusGrid space with the specificed dimensions
        Parameters:
        xSize - size of the x dimension
        ySize - size of the y dimension

      • DoubleDiffuseSpace

        public DoubleDiffuseSpace​(int xSize,
                          int ySize,
                          double diffusionConstant,
                          double evaporationRate)
        Constructs a DblDiffuseTorusGrid space with the specified diffusion constant, evaporation rate, and dimensions
        Parameters:
        diffusionConstant - the diffusion constant
        evaporationRate - the evaporation rate
        xSize - size of the x dimension
        ySize - size of the y dimension

    • Method Detail

      • setDiffusionConstant

        public void setDiffusionConstant​(double diffusionConstant)
        Sets the diffusion constant for this DblDiffuseTorusGrid space

      • setEvaporationRate

        public void setEvaporationRate​(double rate)
        Sets the evaporation rate for this DblDiffuseTorusGrid space

      • diffuse

        public void diffuse()
        Runs the diffusion with the current rates and values. Following the Swarm class, it is roughly newValue = evap(ownValue + diffusionConstant * (nghAvg - ownValue)) where nghAvg is the weighted average of a cells eight neighbors, and ownValue is the current value for the current cell.

        Values from the readMatrix are used to calculate diffusion. This value is then written to the writeMatrix. When this has been done for every cell in the grid, the writeMatrix is copied to the readMatrix.

      • update

        public void update()
        Copies the writeLattice to the readLattice

      • print

        public void print​(double[] mtr)

      • getVonNeumannNeighbors

        public double[] getVonNeumannNeighbors​(int x,
                                       int y)
        Gets the von Neumann neighbors of the specified coordinate. doubles are returned in west, east, north, south order. The double at x, y is not returned.
        Parameters:
        x - the x coordinate of the object
        y - the y coordinate of the object
        Returns:
        an array of doubles in west, east, north, south order

      • getVonNeumannNeighbors

        public double[] getVonNeumannNeighbors​(int x,
                                       int y,
                                       int xExtent,
                                       int yExtent)
        Gets the extended von Neumann neighbors of the specified coordinate. The extension in the x and y direction are specified by xExtent and yExtent. doubles are returned in west, east, north, south order with the most distant object first. The double at x,y is not returned.
        Parameters:
        x - the x coordinate of the object
        y - the y coordinate of the object
        xExtent - the extension of the neighborhood in the x direction
        yExtent - the extension of the neighborhood in the y direction
        Returns:
        an array of doubles in west, east, north, south order with the most distant object first.

      • getMooreNeighbors

        public double[] getMooreNeighbors​(int x,
                                  int y)
        Gets the Moore neighbors of the specified coordinate. doubles are returned by row starting with the "NW corner" and ending with the "SE corner." The double at x, y is not returned.
        Parameters:
        x - the x coordinate of the object
        y - the y coordinate of the object
        Returns:
        an array of doubles ordered by row starting with the "NW corner" and ending with the "SE corner."

      • getMooreNeighbors

        public double[] getMooreNeighbors​(int x,
                                  int y,
                                  int xExtent,
                                  int yExtent)
        Gets the extended Moore neighbors of the specified coordinate. The extension in the x and y direction are specified by xExtent and yExtent. doubles are returned by row starting with the "NW corner" and ending with the "SE corner." The double at x,y is not returned.
        Parameters:
        x - the x coordinate of the object
        y - the y coordinate of the object
        xExtent - the extension of the neighborhood in the x direction
        yExtent - the extension of the neighborhood in the y direction
        Returns:
        an array of doubles ordered by row starting with the "NW corner" and ending with the "SE corner."

      • findMaximum

        public double[] findMaximum​(int x,
                            int y,
                            int range,
                            boolean includeOrigin,
                            int neighborhoodType)
        Finds the maximum grid cell value within a specified range from the specified origin coordinate.
        Parameters:
        x - the x origin coordinate
        y - the y origin coordinate
        range - the range out from the coordinate to search
        includeOrigin - include object at origin in search
        neighborhoodType - the type of neighborhood to search. Can be one of Discrete2DSpace.VON_NEUMANN or Discrete2DSpace.MOORE.
        Returns:
        the Objects determined to be the maximum.

      • findMinimum

        public double[] findMinimum​(int x,
                            int y,
                            int range,
                            boolean includeOrigin,
                            int neighborhoodType)
        Finds the minimum grid cell value within a specified range from the specified origin coordinate.
        Parameters:
        x - the x origin coordinate
        y - the y origin coordinate
        range - the range out from the coordinate to search
        includeOrigin - include object at origin in search
        neighborhoodType - the type of neighborhood to search. Can be one of Discrete2DSpace.VON_NEUMANN or Discrete2DSpace.MOORE.
        Returns:
        the Objects determined to be the maximum.

      • getMatrix

        public double[] getMatrix()
        Description copied from class: DoubleSpace
        Return the matrix of values representing the grid.
        Overrides:
        getMatrix in class DoubleSpace
        Returns:
        A matrix of double with the same dimensions of the grid.

      • onEvent

        public void onEvent​(java.lang.Enum<?> type)
        Specified by:
        onEvent in interface EventListener