AIMS/DrawGraph/Graph/LogScale.cs
2022-08-23 21:12:59 +08:00

444 lines
15 KiB
C#

//============================================================================
//ZedGraph Class Library - A Flexible Line Graph/Bar Graph Library in C#
//Copyright ?2005 John Champion
//
//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
//=============================================================================
using System;
using System.Collections;
using System.Text;
using System.Drawing;
using System.Runtime.Serialization;
using System.Security.Permissions;
namespace DrawGraph
{
/// <summary>
/// The LogScale class inherits from the <see cref="Scale" /> class, and implements
/// the features specific to <see cref="AxisType.Log" />.
/// </summary>
/// <remarks>
/// LogScale is a non-linear axis in which the values are scaled using the base 10
/// <see cref="Math.Log(double)" />
/// function.
/// </remarks>
///
/// <author> John Champion </author>
/// <version> $Revision: 1.12 $ $Date: 2007/04/16 00:03:02 $ </version>
[Serializable]
class LogScale : Scale, ISerializable //, ICloneable
{
#region constructors
/// <summary>
/// Default constructor that defines the owner <see cref="Axis" />
/// (containing object) for this new object.
/// </summary>
/// <param name="owner">The owner, or containing object, of this instance</param>
public LogScale( Axis owner )
: base( owner )
{
}
/// <summary>
/// The Copy Constructor
/// </summary>
/// <param name="rhs">The <see cref="LogScale" /> object from which to copy</param>
/// <param name="owner">The <see cref="Axis" /> object that will own the
/// new instance of <see cref="LogScale" /></param>
public LogScale( Scale rhs, Axis owner )
: base( rhs, owner )
{
}
/// <summary>
/// Create a new clone of the current item, with a new owner assignment
/// </summary>
/// <param name="owner">The new <see cref="Axis" /> instance that will be
/// the owner of the new Scale</param>
/// <returns>A new <see cref="Scale" /> clone.</returns>
public override Scale Clone( Axis owner )
{
return new LogScale( this, owner );
}
#endregion
#region properties
/// <summary>
/// Return the <see cref="AxisType" /> for this <see cref="Scale" />, which is
/// <see cref="AxisType.Log" />.
/// </summary>
public override AxisType Type
{
get { return AxisType.Log; }
}
/// <summary>
/// Gets or sets the minimum value for this scale.
/// </summary>
/// <remarks>
/// The set property is specifically adapted for <see cref="AxisType.Log" /> scales,
/// in that it automatically limits the setting to values greater than zero.
/// </remarks>
public override double Min
{
get { return _min; }
set { if ( value > 0 ) _min = value; }
}
/// <summary>
/// Gets or sets the maximum value for this scale.
/// </summary>
/// <remarks>
/// The set property is specifically adapted for <see cref="AxisType.Log" /> scales,
/// in that it automatically limits the setting to values greater than zero.
/// <see cref="XDate" /> struct.
/// </remarks>
public override double Max
{
get { return _max; }
set { if ( value > 0 ) _max = value; }
}
#endregion
#region methods
/// <summary>
/// Setup some temporary transform values in preparation for rendering the <see cref="Axis"/>.
/// </summary>
/// <remarks>
/// This method is typically called by the parent <see cref="GraphPane"/>
/// object as part of the <see cref="GraphPane.Draw"/> method. It is also
/// called by <see cref="GraphPane.GeneralTransform(double,double,CoordType)"/> and
/// <see cref="GraphPane.ReverseTransform( PointF, out double, out double )"/>
/// methods to setup for coordinate transformations.
/// </remarks>
/// <param name="pane">
/// A reference to the <see cref="GraphPane"/> object that is the parent or
/// owner of this object.
/// </param>
/// <param name="axis">
/// The parent <see cref="Axis" /> for this <see cref="Scale" />
/// </param>
override public void SetupScaleData( GraphPane pane, Axis axis )
{
base.SetupScaleData( pane, axis );
_minLinTemp = Linearize( _min );
_maxLinTemp = Linearize( _max );
}
/// <summary>
/// Convert a value to its linear equivalent for this type of scale.
/// </summary>
/// <remarks>
/// The default behavior is to just return the value unchanged. However,
/// for <see cref="AxisType.Log" /> and <see cref="AxisType.Exponent" />,
/// it returns the log or power equivalent.
/// </remarks>
/// <param name="val">The value to be converted</param>
override public double Linearize( double val )
{
return SafeLog( val );
}
/// <summary>
/// Convert a value from its linear equivalent to its actual scale value
/// for this type of scale.
/// </summary>
/// <remarks>
/// The default behavior is to just return the value unchanged. However,
/// for <see cref="AxisType.Log" /> and <see cref="AxisType.Exponent" />,
/// it returns the anti-log or inverse-power equivalent.
/// </remarks>
/// <param name="val">The value to be converted</param>
override public double DeLinearize( double val )
{
return Math.Pow( 10.0, val );
}
/// <summary>
/// Determine the value for any major tic.
/// </summary>
/// <remarks>
/// This method properly accounts for <see cref="Scale.IsLog"/>, <see cref="Scale.IsText"/>,
/// and other axis format settings.
/// </remarks>
/// <param name="baseVal">
/// The value of the first major tic (floating point double)
/// </param>
/// <param name="tic">
/// The major tic number (0 = first major tic). For log scales, this is the actual power of 10.
/// </param>
/// <returns>
/// The specified major tic value (floating point double).
/// </returns>
override internal double CalcMajorTicValue( double baseVal, double tic )
{
return baseVal + (double)tic * CyclesPerStep;
// double val = baseVal + (double)tic * CyclesPerStep;
// double frac = val - Math.Floor( val );
}
/// <summary>
/// Determine the value for any minor tic.
/// </summary>
/// <remarks>
/// This method properly accounts for <see cref="Scale.IsLog"/>, <see cref="Scale.IsText"/>,
/// and other axis format settings.
/// </remarks>
/// <param name="baseVal">
/// The value of the first major tic (floating point double). This tic value is the base
/// reference for all tics (including minor ones).
/// </param>
/// <param name="iTic">
/// The major tic number (0 = first major tic). For log scales, this is the actual power of 10.
/// </param>
/// <returns>
/// The specified minor tic value (floating point double).
/// </returns>
override internal double CalcMinorTicValue( double baseVal, int iTic )
{
double[] dLogVal = { 0, 0.301029995663981, 0.477121254719662, 0.602059991327962,
0.698970004336019, 0.778151250383644, 0.845098040014257,
0.903089986991944, 0.954242509439325, 1 };
return baseVal + Math.Floor( (double) iTic / 9.0 ) + dLogVal[( iTic + 9 ) % 9];
}
/// <summary>
/// Internal routine to determine the ordinals of the first minor tic mark
/// </summary>
/// <param name="baseVal">
/// The value of the first major tic for the axis.
/// </param>
/// <returns>
/// The ordinal position of the first minor tic, relative to the first major tic.
/// This value can be negative (e.g., -3 means the first minor tic is 3 minor step
/// increments before the first major tic.
/// </returns>
override internal int CalcMinorStart( double baseVal )
{
return -9;
}
/// <summary>
/// Determine the value for the first major tic.
/// </summary>
/// <remarks>
/// This is done by finding the first possible value that is an integral multiple of
/// the step size, taking into account the date/time units if appropriate.
/// This method properly accounts for <see cref="Scale.IsLog"/>, <see cref="Scale.IsText"/>,
/// and other axis format settings.
/// </remarks>
/// <returns>
/// First major tic value (floating point double).
/// </returns>
override internal double CalcBaseTic()
{
if ( _baseTic != PointPair.Missing )
return _baseTic;
else
{
// go to the nearest even multiple of the step size
return Math.Ceiling( Scale.SafeLog( _min ) - 0.00000001 );
}
}
/// <summary>
/// Internal routine to determine the ordinals of the first and last major axis label.
/// </summary>
/// <returns>
/// This is the total number of major tics for this axis.
/// </returns>
override internal int CalcNumTics()
{
int nTics = 1;
//iStart = (int) ( Math.Ceiling( SafeLog( this.min ) - 1.0e-12 ) );
//iEnd = (int) ( Math.Floor( SafeLog( this.max ) + 1.0e-12 ) );
//nTics = (int)( ( Math.Floor( Scale.SafeLog( _max ) + 1.0e-12 ) ) -
// ( Math.Ceiling( Scale.SafeLog( _min ) - 1.0e-12 ) ) + 1 ) / CyclesPerStep;
nTics = (int)( ( Scale.SafeLog( _max ) - Scale.SafeLog( _min ) ) / CyclesPerStep ) + 1;
if ( nTics < 1 )
nTics = 1;
else if ( nTics > 1000 )
nTics = 1000;
return nTics;
}
private double CyclesPerStep
{
//get { return (int)Math.Max( Math.Floor( Scale.SafeLog( _majorStep ) ), 1 ); }
get { return _majorStep; }
}
/// <summary>
/// Select a reasonable base 10 logarithmic axis scale given a range of data values.
/// </summary>
/// <remarks>
/// This method only applies to <see cref="AxisType.Log"/> type axes, and it
/// is called by the general <see cref="PickScale"/> method. The scale range is chosen
/// based always on powers of 10 (full log cycles). This
/// method honors the <see cref="Scale.MinAuto"/>, <see cref="Scale.MaxAuto"/>,
/// and <see cref="Scale.MajorStepAuto"/> autorange settings.
/// In the event that any of the autorange settings are false, the
/// corresponding <see cref="Scale.Min"/>, <see cref="Scale.Max"/>, or <see cref="Scale.MajorStep"/>
/// setting is explicitly honored, and the remaining autorange settings (if any) will
/// be calculated to accomodate the non-autoranged values. For log axes, the MinorStep
/// value is not used.
/// <para>On Exit:</para>
/// <para><see cref="Scale.Min"/> is set to scale minimum (if <see cref="Scale.MinAuto"/> = true)</para>
/// <para><see cref="Scale.Max"/> is set to scale maximum (if <see cref="Scale.MaxAuto"/> = true)</para>
/// <para><see cref="Scale.MajorStep"/> is set to scale step size (if <see cref="Scale.MajorStepAuto"/> = true)</para>
/// <para><see cref="Scale.Mag"/> is set to a magnitude multiplier according to the data</para>
/// <para><see cref="Scale.Format"/> is set to the display format for the values (this controls the
/// number of decimal places, whether there are thousands separators, currency types, etc.)</para>
/// </remarks>
/// <param name="pane">A reference to the <see cref="GraphPane"/> object
/// associated with this <see cref="Axis"/></param>
/// <param name="g">
/// A graphic device object to be drawn into. This is normally e.Graphics from the
/// PaintEventArgs argument to the Paint() method.
/// </param>
/// <param name="scaleFactor">
/// The scaling factor to be used for rendering objects. This is calculated and
/// passed down by the parent <see cref="GraphPane"/> object using the
/// <see cref="PaneBase.CalcScaleFactor"/> method, and is used to proportionally adjust
/// font sizes, etc. according to the actual size of the graph.
/// </param>
/// <seealso cref="PickScale"/>
/// <seealso cref="AxisType.Log"/>
override public void PickScale( GraphPane pane, Graphics g, float scaleFactor )
{
// call the base class first
base.PickScale( pane, g, scaleFactor );
// Majorstep is always 1 for log scales
if ( _majorStepAuto )
_majorStep = 1.0;
_mag = 0; // Never use a magnitude shift for log scales
//this.numDec = 0; // The number of decimal places to display is not used
// Check for bad data range
if ( _min <= 0.0 && _max <= 0.0 )
{
_min = 1.0;
_max = 10.0;
}
else if ( _min <= 0.0 )
{
_min = _max / 10.0;
}
else if ( _max <= 0.0 )
{
_max = _min * 10.0;
}
// Test for trivial condition of range = 0 and pick a suitable default
if ( _max - _min < 1.0e-20 )
{
if ( _maxAuto )
_max = _max * 2.0;
if ( _minAuto )
_min = _min / 2.0;
}
// Get the nearest power of 10 (no partial log cycles allowed)
if ( _minAuto )
_min = Math.Pow( (double) 10.0,
Math.Floor( Math.Log10( _min ) ) );
if ( _maxAuto )
_max = Math.Pow( (double) 10.0,
Math.Ceiling( Math.Log10( _max ) ) );
}
/// <summary>
/// Make a value label for an <see cref="AxisType.Log" /> <see cref="Axis" />.
/// </summary>
/// <param name="pane">
/// A reference to the <see cref="GraphPane"/> object that is the parent or
/// owner of this object.
/// </param>
/// <param name="index">
/// The zero-based, ordinal index of the label to be generated. For example, a value of 2 would
/// cause the third value label on the axis to be generated.
/// </param>
/// <param name="dVal">
/// The numeric value associated with the label. This value is ignored for log (<see cref="Scale.IsLog"/>)
/// and text (<see cref="Scale.IsText"/>) type axes.
/// </param>
/// <returns>The resulting value label as a <see cref="string" /></returns>
override internal string MakeLabel( GraphPane pane, int index, double dVal )
{
if ( _format == null )
_format = Scale.Default.Format;
if ( _isUseTenPower )
return string.Format( "{0:F0}", dVal );
else
return Math.Pow( 10.0, dVal ).ToString( _format );
}
#endregion
#region Serialization
/// <summary>
/// Current schema value that defines the version of the serialized file
/// </summary>
public const int schema2 = 10;
/// <summary>
/// Constructor for deserializing objects
/// </summary>
/// <param name="info">A <see cref="SerializationInfo"/> instance that defines the serialized data
/// </param>
/// <param name="context">A <see cref="StreamingContext"/> instance that contains the serialized data
/// </param>
protected LogScale( SerializationInfo info, StreamingContext context ) : base( info, context )
{
// The schema value is just a file version parameter. You can use it to make future versions
// backwards compatible as new member variables are added to classes
int sch = info.GetInt32( "schema2" );
}
/// <summary>
/// Populates a <see cref="SerializationInfo"/> instance with the data needed to serialize the target object
/// </summary>
/// <param name="info">A <see cref="SerializationInfo"/> instance that defines the serialized data</param>
/// <param name="context">A <see cref="StreamingContext"/> instance that contains the serialized data</param>
[SecurityPermissionAttribute(SecurityAction.Demand,SerializationFormatter=true)]
public override void GetObjectData( SerializationInfo info, StreamingContext context )
{
base.GetObjectData( info, context );
info.AddValue( "schema2", schema2 );
}
#endregion
}
}