DoubleComparer Class

public class DoubleComparer : IComparer, 
	IComparer<double>

Public Class DoubleComparer
	Implements IComparer, IComparer(Of Double)

public ref class DoubleComparer : IComparer, 
	IComparer<double>

type DoubleComparer =  
    class
        interface IComparer
        interface IComparer<float>
    end

The DoubleComparer type exposes the following members.

	Name	Description
	DoubleComparer	Initializes a new instance of the DoubleComparer class.

	Name	Description
	Tolerance	Gets or sets the relative tolerance within which two numbers compare equal.

	Name	Description
	Compare	Compares two Double values and returns a value indicating whether one is less than, equal to or greater than the other.
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Serves as the default hash function. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

Two apparently equivalent floating-point numbers may not compare equal because of differences in their least significant digits. This is usually caused by round-off error resulting from the finite precision of floating-point representations. For example, the C# expression, (double)1/3 == (double)0.33333, does not compare equal because the division operation on the left-hand side has maximum precision while the constant on the right-hand side is only precise to the visible digits.

Instead, determine if the two sides of a comparison are close enough to equal for your purposes. The DoubleComparer class lets you specify the tolerance within which two numbers are considered equal.

Reference