ASP.NET & Csharp (C#)

ASP.NET & Csharp (C#) , Here you can find my posts about .NET c# .

Calculates the floor of the log, base 2, of 'x'.

Posted on by coder 
   
 
    
/*
* CVS identifier:
*
* $Id: MathUtil.java,v 1.15 2001/09/14 08:48:51 grosbois Exp $
*
* Class:                   MathUtil
*
* Description:             Utility mathematical methods
*
*
*
* COPYRIGHT:
* 
* This software module was originally developed by Raphaël Grosbois and
* Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
* Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
* Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
* Centre France S.A) in the course of development of the JPEG2000
* standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
* software module is an implementation of a part of the JPEG 2000
* Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
* Systems AB and Canon Research Centre France S.A (collectively JJ2000
* Partners) agree not to assert against ISO/IEC and users of the JPEG
* 2000 Standard (Users) any of their rights under the copyright, not
* including other intellectual property rights, for this software module
* with respect to the usage by ISO/IEC and Users of this software module
* or modifications thereof for use in hardware or software products
* claiming conformance to the JPEG 2000 Standard. Those intending to use
* this software module in hardware or software products are advised that
* their use may infringe existing patents. The original developers of
* this software module, JJ2000 Partners and ISO/IEC assume no liability
* for use of this software module or modifications thereof. No license
* or right to this software module is granted for non JPEG 2000 Standard
* conforming products. JJ2000 Partners have full right to use this
* software module for his/her own purpose, assign or donate this
* software module to any third party and to inhibit third parties from
* using this software module for non JPEG 2000 Standard conforming
* products. This copyright notice must be included in all copies or
* derivative works of this software module.
* 
* Copyright (c) 1999/2000 JJ2000 Partners.
* */
using System;
namespace CSJ2K.j2k.util
{
  
  /// <summary> This class contains a collection of utility methods fro mathematical
  /// operations. All methods are static.
  /// 
  /// </summary>
  public class MathUtil
  {

    /// <summary> Method that calculates the floor of the log, base 2, of &#039;x&#039;. The
    /// calculation is performed in integer arithmetic, therefore, it is exact.
    /// 
    /// </summary>
    /// <param name="x">The value to calculate log2 on.
    /// 
    /// </param>
    /// <returns> floor(log(x)/log(2)), calculated in an exact way.
    /// 
    /// </returns>
    public static int log2(int x)
    {
      int y, v;
      // No log of 0 or negative
      if (x <= 0)
      {
        throw new System.ArgumentException("" + x + " <= 0");
      }
      // Calculate log2 (it&#039;s actually floor log2)
      v = x;
      y = - 1;
      while (v > 0)
      {
        v >>= 1;
        y++;
      }
      return y;
    }
     }
}

Method that calculates the Greatest Common Divisor (GCD) of two positive integer numbers.

Posted on by coder

/*
* CVS identifier:
*
* $Id: MathUtil.java,v 1.15 2001/09/14 08:48:51 grosbois Exp $
*
* Class: MathUtil
*
* Description: Utility mathematical methods
*
*
*
* COPYRIGHT:
*
* This software module was originally developed by Raphaël Grosbois and
* Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
* Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
* Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
* Centre France S.A) in the course of development of the JPEG2000
* standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
* software module is an implementation of a part of the JPEG 2000
* Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
* Systems AB and Canon Research Centre France S.A (collectively JJ2000
* Partners) agree not to assert against ISO/IEC and users of the JPEG
* 2000 Standard (Users) any of their rights under the copyright, not
* including other intellectual property rights, for this software module
* with respect to the usage by ISO/IEC and Users of this software module
* or modifications thereof for use in hardware or software products
* claiming conformance to the JPEG 2000 Standard. Those intending to use
* this software module in hardware or software products are advised that
* their use may infringe existing patents. The original developers of
* this software module, JJ2000 Partners and ISO/IEC assume no liability
* for use of this software module or modifications thereof. No license
* or right to this software module is granted for non JPEG 2000 Standard
* conforming products. JJ2000 Partners have full right to use this
* software module for his/her own purpose, assign or donate this
* software module to any third party and to inhibit third parties from
* using this software module for non JPEG 2000 Standard conforming
* products. This copyright notice must be included in all copies or
* derivative works of this software module.
*
* Copyright (c) 1999/2000 JJ2000 Partners.
* */
using System;
namespace CSJ2K.j2k.util
{

///

This class contains a collection of utility methods fro mathematical
/// operations. All methods are static.
///
///

public class MathUtil
{

///

Method that calculates the Greatest Common Divisor (GCD) of two
/// positive integer numbers.
///
///

public static int gcd(int x1, int x2)
{
if (x1 < 0 || x2 < 0) { throw new System.ArgumentException("Cannot compute the GCD " + "if one integer is negative."); } int a, b, g, z; if (x1 > x2)
{
a = x1;
b = x2;
}
else
{
a = x2;
b = x1;
}

if (b == 0)
return 0;

g = b;

while (g != 0)
{
z = a % g;
a = g;
g = z;
}
return a;
}

///

Method that calculates the Greatest Common Divisor (GCD) of several
/// positive integer numbers.
///
///

/// Array containing the numbers.
///
/// public static int gcd(int[] x)
{
if (x.Length < 2) { throw new System.ApplicationException("Do not use this method if there are less than" + " two numbers."); } int tmp = gcd(x[x.Length - 1], x[x.Length - 2]); for (int i = x.Length - 3; i >= 0; i–)
{
if (x[i] < 0) { throw new System.ArgumentException("Cannot compute the least " + "common multiple of " + "several numbers where " + "one, at least," + "is negative."); } tmp = gcd(tmp, x[i]); } return tmp; } } } [/csharp]

wraps the mod result to avoid negative results.

Posted on by coder 
   
 

//http://isotopescreencapture.codeplex.com/
//The MIT License (MIT)
namespace Isotope.Math
{
    public static class MathUtil
    {
        /// <summary>
        /// This is a variant of mod that wraps the mod result to avoid negative results. this is what Python&#039;s mod operator does
        /// </summary>
        /// <param name="x"></param>
        /// <param name="y"></param>
        /// <returns></returns>
        private static double mod_wrap_angle(double x, double y)
        {
            if (y == 0)
            {
                throw new System.DivideByZeroException();
            }

            double r = x%y;
            if (r > 0 &amp;&amp; y < 0)
            {
                r = r + y;
            }
            else if (r < 0 &amp;&amp; y > 0)
            {
                r = r + y;
            }
            return r;
        }

        /// <summary>
        /// wraps a number around so that it always fits between 0.0 and 1.0. negative numbers will wrap around to the correct positive number
        /// </summary>
        /// <remarks>
        /// if the input number is already in the range, no change will occur
        /// </remarks>
        /// <param name="v">input value </param>
        /// <returns>the wrapped number</returns>
        public static double WrapAngle_0_1(double v)
        {
            const double min = 0.0;
            const double max = 1.0;
            if (IsInRange(v, min, max))
            {
                // the number is already in the range so do nothing
                return v;
            }
            return mod_wrap_angle(v, max);
        }
        /// <summary>
        /// Checks if a value is in a range (inclusive)
        /// </summary>
        /// <param name="val"></param>
        /// <param name="min"></param>
        /// <param name="max"></param>
        /// <returns></returns>
        public static bool IsInRange(double val, double min, double max)
        {
            return ((min <= val) &amp;&amp; (val <= max));
        }

        /// <summary>
        /// Checks if a value is in the range 0.0 to 1.0 inclusive
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static bool IsInRange_0_1(double val)
        {
            return IsInRange(val, 0.0, 1.0);
        }        
   }
}

Combines two input numbers in some proportion.

Posted on by coder 
   
 

//http://isotopescreencapture.codeplex.com/
//The MIT License (MIT)
namespace Isotope.Math
{
    public static class MathUtil
    {
        /// <summary>
        /// Combines two input numbers in some proportion. 
        /// ratio=0.0 the first number is not used at all, 
        /// ratio=0.5 they are weight equally
        /// ratio=1.0 the first number completely dominates the value
        /// </summary>
        /// <param name="val0"></param>
        /// <param name="val1"></param>
        /// <param name="ratio"></param>
        /// <returns></returns>
        public static double Blend_0_1(double val0, double val1, double ratio)
        {
            var cratio = ClampToRange_0_1(ratio);
            var v0 = val0*cratio;
            var v1 = val1*(1.0 - cratio);
            return v0 + v1;
        }
        /// <summary>
        /// Given an input value will force the value to fit within the range (min,max) inclusive
        /// </summary>
        /// <param name="v"></param>
        /// <param name="min"></param>
        /// <param name="max"></param>
        /// <returns></returns>
        public static double ClampToRange(double v, double min, double max)
        {
            if (v < min)
            {
                v = min;
            }
            else if (v > max)
            {
                v = max;
            }
            return v;
        }

        /// <summary>
        /// Given an input value, will limit it to the range 0.0 and 1.0 inclusive
        /// </summary>
        /// <param name="v"></param>
        /// <returns>the clamped value</returns>
        public static double ClampToRange_0_1(double v)
        {
            return ClampToRange(v, 0.0, 1.0);
        }

    }
}

rounds val to the nearest fractional value

Posted on by coder

//http://isotopescreencapture.codeplex.com/
//The MIT License (MIT)
namespace Isotope.Math
{
public static class MathUtil
{
public static double Round(double val, double snap_val)
{
return Round(val, System.MidpointRounding.AwayFromZero, snap_val);
}
///

/// rounds val to the nearest fractional value
///

/// the value tp round /// what kind of rounding /// round to this value (must be greater than 0.0) /// the rounded value
public static double Round(double val, System.MidpointRounding rounding, double frac)
{
/*
if (frac <= 0) { throw new ArgumentOutOfRangeException("frac","must be greater than or equal to 0.0"); }*/ double retval = System.Math.Round((val/frac), rounding)*frac; return retval; } public static double RoundUp(double v, double amount) { const System.MidpointRounding rounding = System.MidpointRounding.ToEven; var result = Round(v + (amount/2.0), rounding, amount); return result; } } } [/csharp]

Returns the minimum value of three numbers

Posted on by coder 
   
 

//http://isotopescreencapture.codeplex.com/
//The MIT License (MIT)
namespace Isotope.Math
{
    public static class MathUtil
    {
        /// <summary>
        /// Returns the minimum value of three numbers
        /// </summary>
        /// <param name="a"></param>
        /// <param name="b"></param>
        /// <param name="c"></param>
        /// <returns></returns>
        public static double Min(double a, double b, double c)
        {
            return (System.Math.Min(System.Math.Min(a, b), c));
        }
   }
}