dataset.java

java 作图的程序

package graph;

import java.awt.*;
import java.applet.*;
import java.util.*;
import java.lang.*;


/*
**************************************************************************
**
**    Class  DataSet
**
**************************************************************************
**    Copyright (C) 1995, 1996 Leigh Brookshaw
**
**    This program is free software; you can redistribute it and/or modify
**    it under the terms of the GNU General Public License as published by
**    the Free Software Foundation; either version 2 of the License, or
**    (at your option) any later version.
**
**    This program 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 General Public License for more details.
**
**    You should have received a copy of the GNU General Public License
**    along with this program; if not, write to the Free Software
**    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**************************************************************************
**
**    This class is designed to be used in conjunction with 
**    the Graph2D class and Axis class for plotting 2D graphs.
**
*************************************************************************/


/**
 *  This class is designed to hold the data to be plotted.
 *  It is to be used in conjunction with the Graph2D class and Axis 
 *  class for plotting 2D graphs.
 *
 * @version $Revision: 1.15 $, $Date: 1996/09/24 05:23:41 $
 * @author Leigh Brookshaw 
 */
public class DataSet extends Object {


/*
***************************
** Public Static Values     
**************************/
/**
 *    A constant value flag used to specify no straight line segment
 *    is to join the data points
 */
      public final static int NOLINE    =  0;
/**
 *    A constant value flag used to specify that a straight line segment
 *    is to join the data points.
 */
      public final static int LINE      =  1;



/*
***********************
** Public Variables      
**********************/

  /** 
   *    The Graphics canvas that is driving the whole show.
   * @see graph.Graph2D
   */
      public Graph2D g2d;

  /**
   *    The linestyle to employ when joining the data points with
   *    straight line segments. Currently only solid and no line
   *    are supported.
   */
      public int   linestyle     = LINE;
  /**
   *    The color of the straight line segments
   */
      public Color linecolor     = null;
  /**
   *    The index of the marker to use at the data points.
   * @see graph.Markers
   */
      public int    marker       = 0;
  /**
   *    The marker color
   */
      public Color  markercolor  = null;
  /**
   *    The scaling factor for the marker. Default value is 1.
   */
      public double markerscale  = 1.0;
  /**
   *    The Axis object the X data is attached to. From the Axis object
   *    the scaling for the data can be derived.
   * @see graph.Axis
   */
      public Axis xaxis;
  /**
   *    The Axis object the Y data is attached to.
   * @see graph.Axis
   */
      public Axis yaxis;
  /**
   * The current plottable X maximum of the data. 
   * This can be very different from
   * true data X maximum. The data is clipped when plotted.
   */
      public double xmax; 
  /**
   * The current plottable X minimum of the data. 
   * This can be very different from
   * true data X minimum. The data is clipped when plotted.
   */
      public double xmin;
  /**
   * The current plottable Y maximum of the data. 
   * This can be very different from
   * true data Y maximum. The data is clipped when plotted.
   */
      public double ymax; 
  /**
   * The current plottable Y minimum of the data. 
   * This can be very different from
   * true data Y minimum. The data is clipped when plotted.
   */
      public double ymin;
  /**
   * Boolean to control clipping of the data window.
   * Default value is <em>true</em>, clip the data window.
   */
      public boolean clipping = true;


/*
*********************
** Protected Variables      
**********************/

  /**
   * The data X maximum. 
   * Once the data is loaded this will never change.
   */
      protected double dxmax;
  /**
   * The data X minimum. 
   * Once the data is loaded this will never change.
   */
      protected double dxmin;
  /**
   * The data Y maximum. 
   * Once the data is loaded this will never change.
   */
      protected double dymax;
  /**
   * The data Y minimum. 
   * Once the data is loaded this will never change.
   */
      protected double dymin;

  /**
   * The array containing the actual data 
   */
      protected double data[];
  /**
   * The number of data points stored in the data array
   */
      protected int length;
  /**
   *    The X range of the clipped data
   */
      protected double xrange;
  /**
   *    The Y range of the clipped data
   */
      protected double yrange;

  /**
   *    The length of the example line in the data legend.
   */
      protected int legend_length = 20;

  /**
   *    The legend text
   */
      protected TextLine legend_text = null;
  /**
   * The X pixel position of the data legend
   */
      protected int legend_ix;
  /**
   * The Y pixel position of the data legend
   */
      protected int legend_iy;
  /**
   * The X data position of the data legend
   */
      protected double legend_dx;
  /**
   * The Y data position of the data legend
   */
      protected double legend_dy;
  /**
   *    The amount to increment the data array when the append method is being
   *    used.
   */
      protected int increment = 100;


  /**
   * The stride of the data. For data pairs (x,y) the stride is 2
   */
    protected int stride = 2;

/*
*********************
** Constructors
********************/

  /**
   *  Instantiate an empty data set.
   */
      public DataSet ( ) {
               length = 0;
               range(stride);
      }
  /**
   *  Instantiate an empty data set.
   *  @param stride the stride of the data set. The default stride is 2.
   */
      public DataSet (int stride ) throws Exception {
               if( stride < 2 ) throw 
                          new Exception("Invalid stride parameter!");
               this.stride = stride;
               length = 0;
               range(stride);
      }

  /**
   * Instantiate a DataSet with the parsed data. Default stride is 2.
   * The double array contains the data. The X data is expected in
   * the even indices, the y data in the odd. The integer n is the
   * number of data Points. This means that the length of the data
   * array is 2*n.
   * @param d Array containing the (x,y) data pairs.
   * @param n Number of (x,y) data pairs in the array.
   * @exception  Exception
   *            A Generic exception if it fails to load the
   *            parsed array into the class.
   */
      public DataSet ( double d[], int n ) throws Exception {
           int i;
           int k = 0;

           length = 0;

           if ( d  == null || d.length == 0 || n <= 0 ) {
              throw new Exception("DataSet: Error in parsed data!");
           }

//     Copy the data locally.

           data = new double[n*stride];
           length = n*stride;

           System.arraycopy(d, 0, data, 0, length);


//     Calculate the data range.

           range(stride);


      }

  /**
   * Instantiate a DataSet with the parsed data.
   * The double array contains the data. The X data is expected to be in
   * indices i*stride where i=0,1,... The Y data is expected to be found
   * in indices i*stride+1 where i=0,1,2...
   * The integer n is the
   * number of data Points. This means that the length of the data
   * array is 2*stride.
   * @param d Array containing the (x,y) data pairs.
   * @param n Number of (x,y) data pairs in the array.
   * @param s The stride of the data.
   * @exception  Exception
   *            A Generic exception if it fails to load the
   *            parsed array into the class.
   */
      public DataSet ( double d[], int n, int s ) throws Exception {
          if( s < 2 ) throw 
                          new Exception("Invalid stride parameter!");
           int i;
           int k = 0;

           length = 0;

           if ( d  == null || d.length == 0 || n <= 0 ) {
              throw new Exception("DataSet: Error in parsed data!");
           }

           this.stride = s;


//     Copy the data locally.

           data = new double[n*stride];
           length = n*stride;

           System.arraycopy(d, 0, data, 0, length);


//     Calculate the data range.

           range(stride);
      }
/*
*******************
** Public Methods
******************/

  /**
   * Append data to the data set.
   * @param d Array containing (x,y) pairs to append
   * @param n Number of (x,y) data pairs in the array.
   * @exception Exception
   *          A generic exception if it fails to load the
   *            parsed array into the class.
   */
      public void append( double d[], int n ) throws Exception {
           int i;
           int k = 0;
           double tmp[];
           int ln = n*stride;

           if ( d  == null || d.length == 0 || n <= 0 ) {
              throw new Exception("DataSet: Error in append data!");
           }

           if(data == null) data = new double[increment];

//     Copy the data locally.


           if( ln+length < data.length ) {
               System.arraycopy(d, 0, data, length, ln);
               length += ln;
	   } else {
               tmp = new double[ln+length+increment];

               if( length != 0 ) {
                 System.arraycopy(data, 0, tmp, 0, length);
               }
               System.arraycopy(d, 0, tmp, length, ln);

               length += ln;
               data = tmp;
	     }

//     Calculate the data range.

           range(stride);
//     Update the range on Axis that this data is attached to
           if(xaxis != null) xaxis.resetRange();
           if(yaxis != null) yaxis.resetRange();



      }
  /**
   * Delete data from the data set (start and end are inclusive).
   * The first (x,y) pair in the data set start at index 0.
   * @param start The start (x,y) pair index.
   * @param end   The end (x,y) pair index.
   */
      public void  delete( int start, int end ) {
           int End   = stride*end;
           int Start = stride*start;

           if(length <= 0) return;

           if( End   < Start )         return;
           if( Start < 0 )             Start = 0;
           if( End > length-stride )        End = length-stride;

           if( End < length-stride) {
               System.arraycopy(data, End+stride, 
                                data, Start, length - End - stride);
	     }

           length -= End+stride-Start;


//     Calculate the data range.

           range(stride);


      }
  /**
   * Delete all the data from the data set.
   */
      public void  deleteData( ) {
           length = 0;
           data = null;
           range(stride);
      }

  /**
   * Draw the straight line segments and/or the markers at the
   * data points.
   * If this data has been attached to an Axis then scale the data
   * based on the axis maximum/minimum otherwise scale using
   * the data's maximum/minimum
   * @param g Graphics state
   * @param bounds The data window to draw into