intgrid2d.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 ints.

   <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 IntGrid2D extends AbstractGrid2D
    {
    public int[/**x*/][/**y*/] field;
    
    public IntGrid2D (int width, int height)
        {
        this.width = width;
        this.height = height;
        field = new int[width][height];
        }
    
    public IntGrid2D (int width, int height, int initialValue)
        {
        this(width,height);
        setTo(initialValue);
        }
    
    public IntGrid2D (IntGrid2D values)
        {
        setTo(values);
        }

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

    /** Sets all the locations in the grid the provided element */
    public final IntGrid2D setTo(int thisMuch)
        {
        int[] 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 IntGrid2D setTo(IntGrid2D values)
        {
        if (width != values.width || height != values.height)
            {
            final int width = this.width = values.width;
            final int height = this.height = values.height;
            field = new int[width][];
            for(int x =0 ; x < width; x++)
                field[x] = (int []) (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 int max()
        {
        int max = Integer.MIN_VALUE;
        int[] 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 (max < fieldx[y]) max = fieldx[y];
            }
        return max;
        }

    /** Returns the minimum value stored in the grid */
    public final int min()
        {
        int min = Integer.MAX_VALUE;
        int[] 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 (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;
        int[] 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 IntGrid2D upperBound(int toNoMoreThanThisMuch)
        {
        int[] 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 IntGrid2D lowerBound(int toNoLowerThanThisMuch)
        {
        int[] 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 IntGrid2D add(int withThisMuch)
        {
        if (withThisMuch==0.0) return this;
        int[] 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]+=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 IntGrid2D add(IntGrid2D withThis)
        {
        int[][]ofield = withThis.field;
        int[] ofieldx = null;
        int[] fieldx = null;
        final int width = this.width;
        final int height = this.height;
        for(int x=0;x<width;x++)
            {
            fieldx = field[x];
            ofieldx = ofield[x];
            for(int y=0;y<height;y++)
                fieldx[y]+=ofieldx[y];
            }
        return this;
        }

    /** Sets each value in the grid to that value multiplied <i>byThisMuch</i>
        Returns the modified grid. 
    */

    public final IntGrid2D multiply(int byThisMuch)
        {
        if (byThisMuch==1.0) return this;
        int[] 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]*=byThisMuch;
            }
        return this;
        }
    
    /** Sets the value at each location in the grid to that value multiplied by to the value at the equivalent location in the provided grid.
        Returns the modified grid. 
    */

    public final IntGrid2D multiply(IntGrid2D withThis)
        {
        int[][]ofield = withThis.field;
        int[] ofieldx = null;
        int[] fieldx = null;
        final int width = this.width;
        final int height = this.height;
        for(int x=0;x<width;x++)
            {
            fieldx = field[x];
            ofieldx = ofield[x];
            for(int y=0;y<height;y++)
                fieldx[y]*=ofieldx[y];
            }
        return this;
        }


    /**
     * Gets all neighbors of a location that satisfy max( abs(x-X) , abs(y-Y) ) <= dist.  This region forms a
     * square 2*dist+1 cells across, centered at (X,Y).  If dist==1, this
     * is equivalent to the so-called "Moore Neighborhood" (the eight neighbors surrounding (X,Y)), plus (X,Y) itself.
     * Places each x and y value of these locations in the provided IntBags xPos and yPos, clearing the bags first.
     * Then places into the result IntBag the elements at each of those <x,y> locations clearning it first.  
     * Returns the result IntBag (constructing one if null had been passed in).
     * null may be passed in for the various bags, though it is more efficient to pass in a 'scratch bag' for
     * each one.
     */
    public final IntBag getNeighborsMaxDistance( final int x, final int y, final int dist, final boolean toroidal, IntBag result, IntBag xPos, IntBag yPos )
        {
        if( xPos == null )
            xPos = new IntBag();
        if( yPos == null )
            yPos = new IntBag();
        if (result == null)
            result = new IntBag();

        getNeighborsMaxDistance( x, y, dist, toroidal, xPos, yPos );

        result.clear();
        for( int i = 0 ; i < xPos.numObjs ; i++ )
            result.add( field[xPos.objs[i]][yPos.objs[i]] );
        return result;
        }

    /**
     * Gets all neighbors of a location that satisfy abs(x-X) + abs(y-Y) <= dist.  This region forms a diamond
     * 2*dist+1 cells from point to opposite point inclusive, centered at (X,Y).  If dist==1 this is
     * equivalent to the so-called "Von-Neumann Neighborhood" (the four neighbors above, below, left, and right of (X,Y)),
     * plus (X,Y) itself.
     * Places each x and y value of these locations in the provided IntBags xPos and yPos, clearing the bags first.
     * Then places into the result IntBag the elements at each of those <x,y> locations clearning it first.  
     * Returns the result IntBag (constructing one if null had been passed in).
     * null may be passed in for the various bags, though it is more efficient to pass in a 'scratch bag' for
     * each one.
     */
    public final IntBag getNeighborsHamiltonianDistance( final int x, final int y, final int dist, final boolean toroidal, IntBag result, IntBag xPos, IntBag yPos )
        {
        if( xPos == null )
            xPos = new IntBag();
        if( yPos == null )
            yPos = new IntBag();
        if (result == null)
            result = new IntBag();

        getNeighborsHamiltonianDistance( x, y, dist, toroidal, xPos, yPos );

        result.clear();
        for( int i = 0 ; i < xPos.numObjs ; i++ )
            result.add( field[xPos.objs[i]][yPos.objs[i]] );
        return result;
        }

    /**
     * Gets all neighbors located within the hexagon centered at (X,Y) and 2*dist+1 cells from point to opposite point 
     * inclusive.
     * If dist==1, this is equivalent to the six neighbors immediately surrounding (X,Y), 
     * plus (X,Y) itself.
     * Places each x and y value of these locations in the provided IntBags xPos and yPos, clearing the bags first.
     * Then places into the result IntBag the elements at each of those <x,y> locations clearning it first.  
     * Returns the result IntBag (constructing one if null had been passed in).
     * null may be passed in for the various bags, though it is more efficient to pass in a 'scratch bag' for
     * each one.
     */
    public final IntBag getNeighborsHexagonalDistance( final int x, final int y, final int dist, final boolean toroidal, IntBag result, IntBag xPos, IntBag yPos )
        {
        if( xPos == null )
            xPos = new IntBag();
        if( yPos == null )
            yPos = new IntBag();
        if (result == null)
            result = new IntBag();

        getNeighborsHexagonalDistance( x, y, dist, toroidal, xPos, yPos );

        result.clear();
        for( int i = 0 ; i < xPos.numObjs ; i++ )
            result.add( field[xPos.objs[i]][yPos.objs[i]] );
        return result;
        }

    }