source: branches/HeuristicLab.Problems.GrammaticalOptimization/DynamicDataDisplay/Transforms/Log10Transform.cs @ 13757

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;

namespace Microsoft.Research.DynamicDataDisplay
{
  /// <summary>
  /// Represents a logarithmic transform of both x- and y-values.
  /// </summary>
  public sealed class Log10Transform : DataTransform
  {
    /// <summary>
    /// Initializes a new instance of the <see cref="Log10Transform"/> class.
    /// </summary>
    public Log10Transform() { }

    /// <summary>
    /// Transforms the point in data coordinates to viewport coordinates.
    /// </summary>
    /// <param name="pt">The point in data coordinates.</param>
    /// <returns>
    /// Transformed point in viewport coordinates.
    /// </returns>
    public override Point DataToViewport(Point pt)
    {
      double x = pt.X;
      double y = pt.Y;

      x = x < 0 ? Double.MinValue : Math.Log10(x);
      y = y < 0 ? Double.MinValue : Math.Log10(y);

      return new Point(x, y);
    }

    /// <summary>
    /// Transforms the point in viewport coordinates to data coordinates.
    /// </summary>
    /// <param name="pt">The point in viewport coordinates.</param>
    /// <returns>Transformed point in data coordinates.</returns>
    public override Point ViewportToData(Point pt)
    {
      return new Point(Math.Pow(10, pt.X), Math.Pow(10, pt.Y));
    }

    /// <summary>
    /// Gets the data domain of this dataTransform.
    /// </summary>
    /// <value>The data domain of this dataTransform.</value>
    public override DataRect DataDomain
    {
      get { return DataDomains.XYPositive; }
    }
  }
}