doublegrid2d.java

MASON代表多主体邻里或网络仿真(Multi-Agent Simulator of Neighborhoods or Networks)。它是乔治梅森大学用Java开发的离散事件多主体仿真核心库

package sim.field.grid;
import sim.util.*;
/** 
    A wrapper for 2D arrays of doubles.

    <p>This object expects that the 2D arrays are rectangular.  You are encouraged to access the array
    directly.  The object
    implements all of the Grid2D interface.  See Grid2D for rules on how to properly implement toroidal
    or hexagonal grids.
    
    <p>The width and height of the object are provided to avoid having to say field[x].length, etc.  
*/

public /*strictfp*/ class DoubleGrid2D extends AbstractGrid2D
    {
    public double[/**x*/][/**y*/] field;
    
    public double[][] getField() { return field; }
    
    public DoubleGrid2D (int width, int height)
        {
        this.width = width;
        this.height = height;
        field = new double[width][height];
        }
    
    public DoubleGrid2D (int width, int height, double initialValue)
        {
        this(width,height);
        setTo(initialValue);
        }
        
    public DoubleGrid2D (DoubleGrid2D values)
        {
        setTo(values);
        }

    /** Sets location (x,y) to val */
    public final void set(final int x, final int y, final double val)
        {
        field[x][y] = val;
        }
    
    /** Returns the element at location (x,y) */
    public final double get(final int x, final int y)
        {
        return field[x][y];
        }

    /** Sets all the locations in the grid the provided element */
    public final DoubleGrid2D setTo(final double thisMuch)
        {
        double[] fieldx = null;
        final int width = this.width;
        final int height = this.height;
        for(int x=0;x<width;x++)
            {
            fieldx = field[x]; 
            for(int y=0;y<height;y++)
                fieldx[y]=thisMuch;
            }
        return this;
        }

    /** Changes the dimensions of the grid to be the same as the one provided, then
        sets all the locations in the grid to the elements at the quivalent locations in the
        provided grid. */
    public final DoubleGrid2D setTo(final DoubleGrid2D values)
        {
        if (width != values.width || height != values.height)
            {
            final int width = this.width = values.width;
            final int height = this.height = values.height;
            field = new double[width][];
            for(int x =0 ; x < width; x++)
                field[x] = (double []) (values.field[x].clone());
            }
        else
            {
            for(int x =0 ; x < width; x++)
                System.arraycopy(values.field[x],0,field[x],0,height);
            }
        return this;
        }

    /** Returns the maximum value stored in the grid */
    public final double max()
        {
        double max = Double.NEGATIVE_INFINITY;
        final int width = this.width;
        final int height = this.height;        
        double[] fieldx = null;
        for(int x=0;x<width;x++)
            {
            fieldx = field[x]; 
            for(int y=0;y<height;y++)
                if (max < fieldx[y]) max = fieldx[y];
            }
        return max;
        }

    /** Returns the minimum value stored in the grid */
    public final double min()
        {
        double min = Double.POSITIVE_INFINITY;
        final int width = this.width;
        final int height = this.height;
        double[] fieldx = null;
        for(int x=0;x<width;x++)
            {
            fieldx = field[x]; 
            for(int y=0;y<height;y++)
                if (min > fieldx[y]) min = fieldx[y];
            }
        return min;
        }
        
    /** Returns the mean value stored in the grid */
    public final double mean()
        {
        long count = 0;
        double mean = 0;
        double[] fieldx = null;
        final int width = this.width;
        final int height = this.height;
        for(int x=0;x<width;x++)
            {
            fieldx = field[x]; 
            for(int y=0;y<height;y++)
                { mean += fieldx[y]; count++; }
            }
        return (count == 0 ? 0 : mean / count);
        }
        
    /** Thresholds the grid so that values greater to <i>toNoMoreThanThisMuch</i> are changed to <i>toNoMoreThanThisMuch</i>.
        Returns the modified grid. 
    */
    public final DoubleGrid2D upperBound(final double toNoMoreThanThisMuch)
        {
        double[] fieldx = null;
        final int width = this.width;
        final int height = this.height;
        for(int x=0;x<width;x++)
            {
            fieldx = field[x]; 
            for(int y=0;y<height;y++)
                if (fieldx[y] > toNoMoreThanThisMuch)
                    fieldx[y] = toNoMoreThanThisMuch;
            }
        return this;
        }

    /** Thresholds the grid so that values smaller than <i>toNoLowerThanThisMuch</i> are changed to <i>toNoLowerThanThisMuch</i>
        Returns the modified grid. 
    */
    public final DoubleGrid2D lowerBound(final double toNoLowerThanThisMuch)
        {
        double[] fieldx = null;
        final int width = this.width;
        final int height = this.height;
        for(int x=0;x<width;x++)
            {
            fieldx = field[x]; 
            for(int y=0;y<height;y++)
                if (fieldx[y] < toNoLowerThanThisMuch)
                    fieldx[y] = toNoLowerThanThisMuch;
            }
        return this;
        }
    
    /** Sets each value in the grid to that value added to <i>withThisMuch</i>
        Returns the modified grid. 
    */
    public final DoubleGrid2D add(final double withThisMuch)
        {
        final int width = this.width;
        final int height = this.height;
        if (withThisMuch==0.0) return this;
        double[] fieldx = null;
        for(int x=0;x<width;x++)
            {
            fieldx = field[x]; 
            for(int y=0;y<height;y++)
                fieldx[y]+=withThisMuch;
            }
        return this;
        }
        
    /** Sets the value at each location in the grid to that value added to the value at the equivalent location in the provided grid.
        Returns the modified grid. 
    */
    public final DoubleGrid2D add(final IntGrid2D withThis)
        {
        final int[][] otherField = withThis.field;
        double[] fieldx = null;
        int[] ofieldx = null;
        final int width = this.width;
        final int height = this.height;
        for(int x=0;x<width;x++)
            {
            fieldx = field[x];
            ofieldx = otherField[x];
            for(int y=0;y<height;y++)
                fieldx[y]+=ofieldx[y];
            }
        return this;
        }

    /** Sets the value at each location in the grid to that value added to the value at the equivalent location in the provided grid.
        Returns the modified grid. 
    */
    public final DoubleGrid2D add(final DoubleGrid2D withThis)
        {
        final double[][] otherField = withThis.field;
        double[] fieldx = null;
        double[] ofieldx = null;
        final int width = this.width;
        final int height = this.height;
        for(int x=0;x<width;x++)
            {
            fieldx = field[x]; 
            ofieldx = otherField[x];
            for(int y=0;y<height;y++)