/**
 * Version 1.0 is to handle single variable 2DSquareCelled raster data.
 * Copyright (C) 2005 Andy Turner, CCG, University of Leeds, UK.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */
package uk.ac.leeds.ccg.andyt.grids.core;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.io.Serializable;

/**
 * Used by AbstractGrid2DSquareCell instances to access statistics. This class 
 * to be instantiated for AbstractGrid2DSquareCell that do not keep all 
 * statistic fields up to date as the underlying data is changed. (Keeping 
 * statistic fields up to date as the underlying data is changed can be 
 * expensive.)
 */
public class GridStatistics1 
        extends AbstractGridStatistics 
        implements Serializable {
    
    private static final long serialVersionUID = 1L; 

    /** Creates a new instance of GridStatistics1 */
    public GridStatistics1() {
    }
    
    /**
     * Creates a new instance of GridStatistics1
     * 
     * @param _Grid2DSquareCell
     */
    public GridStatistics1( 
            AbstractGrid2DSquareCell _Grid2DSquareCell ) {
        init( _Grid2DSquareCell );
    }
    
    /**
     * Is true iff fields are upToDate else is false.
     */
    protected  boolean isUpToDate;
    
    /**
     * Returns upToDate
     */
    protected boolean getIsUpToDate() {
        return isUpToDate;
    }
    
    /**
     * Sets this.isUpToDate to isUpToDate
     */
    protected void setIsUpToDate( 
            boolean isUpToDate ) {
        this.isUpToDate = isUpToDate;
    }
    
    /**
     * Updates fields (statistics) by going through all values in
     * this.grid2DSquareCellAbstract if they might not be up to date.
     * (NB. After calling this it is inexpensive to convert to GridStatistics0.)
     */
    protected @Override void update() {
        if ( ! getIsUpToDate() ) {
            init();
            super.update( 
                    this._Grid2DSquareCell._NRows, 
                    this._Grid2DSquareCell._NCols );
            setIsUpToDate( true );
        }
    }

    /**
     * For returning the number of cells with noDataValues as a BigInteger
     */
    protected @Override BigInteger getNonNoDataValueCountBigInteger() {
        update();
        return this.nonNoDataValueCountBigInteger;
    }
    
    /**
     * For returning the sum of all non noDataValues as a BigDecimal
     */
    protected @Override BigDecimal getSumBigDecimal() {
        update();
        return this.sumBigDecimal;
    }
    
    /**
     * For returning the minimum of all non noDataValues as a BigDecimal
     */
    protected @Override BigDecimal getMinBigDecimal() {
        update();
        return this.minBigDecimal;
    }
    
    /**
     * For returning the maximum of all non noDataValues as a BigDecimal
     */
    protected @Override BigDecimal getMaxBigDecimal() {
        update();
        return this.maxBigDecimal;
    }
    
    /**
     * For returning the arithmetic mean of all non noDataValues as a BigDecimal
     * Throws an ArithmeticException if nonNoDataValueCountBigInteger is equal
     * to zero.
     */
    protected @Override BigDecimal getArithmeticMeanBigDecimal( 
            int numberOfDecimalPlaces ) {
        update();
        return this.sumBigDecimal.divide( 
                new BigDecimal( this.nonNoDataValueCountBigInteger ), 
                numberOfDecimalPlaces, 
                BigDecimal.ROUND_HALF_EVEN );
    }
    
}