แก้ไข

แชร์ผ่าน

Complex.FromPolarCoordinates(Double, Double) Method

  • Reference

Definition

Namespace:
System.Numerics
Assembly:
System.Runtime.Numerics.dll
Assembly:
System.Numerics.dll
Assembly:
netstandard.dll
Source:
Complex.cs
Source:
Complex.cs
Source:
Complex.cs

Creates a complex number from a point's polar coordinates.

public:
 static System::Numerics::Complex FromPolarCoordinates(double magnitude, double phase);
public static System.Numerics.Complex FromPolarCoordinates (double magnitude, double phase);
static member FromPolarCoordinates : double * double -> System.Numerics.Complex
Public Shared Function FromPolarCoordinates (magnitude As Double, phase As Double) As Complex

Parameters

magnitude
Double

The magnitude, which is the distance from the origin (the intersection of the x-axis and the y-axis) to the number.

phase
Double

The phase, which is the angle from the line to the horizontal axis, measured in radians.

Returns

Complex

A complex number.

Examples

The following example uses the FromPolarCoordinates method to instantiate a complex number based on its polar coordinates and then displays the value of its Magnitude and Phase properties.

using System;
using System.Numerics;

public class Example
{
   public static void Main()
   {
      Complex c1 = Complex.FromPolarCoordinates(10, 45 * Math.PI / 180);
      Console.WriteLine("{0}:", c1);
      Console.WriteLine("   Magnitude: {0}", Complex.Abs(c1));
      Console.WriteLine("   Phase:     {0} radians", c1.Phase);
      Console.WriteLine("   Phase      {0} degrees", c1.Phase * 180/Math.PI);
      Console.WriteLine("   Atan(b/a): {0}", Math.Atan(c1.Imaginary/c1.Real));
   }
}
// The example displays the following output:
//       (7.07106781186548, 7.07106781186547):
//          Magnitude: 10
//          Phase:     0.785398163397448 radians
//          Phase      45 degrees
//          Atan(b/a): 0.785398163397448

open System
open System.Numerics

let c1 = Complex.FromPolarCoordinates(10., 45. * Math.PI / 180.)
printfn $"{c1}:"
printfn $"   Magnitude: {Complex.Abs(c1)}"
printfn $"   Phase:     {c1.Phase} radians"
printfn $"   Phase      {c1.Phase * 180. / Math.PI} degrees"
printfn $"   Atan(b/a): {Math.Atan(c1.Imaginary / c1.Real)}"
// The example displays the following output:
//       (7.07106781186548, 7.07106781186547):
//          Magnitude: 10
//          Phase:     0.785398163397448 radians
//          Phase      45 degrees
//          Atan(b/a): 0.785398163397448

Imports System.Numerics

Module Example
   Public Sub Main()
      Dim c1 As Complex = Complex.FromPolarCoordinates(10, 45 * Math.Pi / 180)
      Console.WriteLine("{0}:", c1)
      Console.WriteLine("   Magnitude: {0}", Complex.Abs(c1))
      Console.WriteLine("   Phase:     {0} radians", c1.Phase)
      Console.WriteLine("   Phase      {0} degrees", c1.Phase * 180/Math.Pi)
      Console.WriteLine("   Atan(b/a): {0}", Math.Atan(c1.Imaginary/c1.Real))
   End Sub
End Module
' The example displays the following output:
'       (7.07106781186548, 7.07106781186547):
'          Magnitude: 10
'          Phase:     0.785398163397448 radians
'          Phase      45 degrees
'          Atan(b/a): 0.785398163397448

Remarks

The FromPolarCoordinates method instantiates a complex number based on its polar coordinates.

Because there are multiple representations of a point on a complex plane, the return value of the FromPolarCoordinates method is normalized. The magnitude is normalized to a positive number, and the phase is normalized to a value in the range of -PI to PI. As a result, the values of the Phase and Magnitude properties of the resulting complex number might not equal the original values of the magnitude and phase parameters.

To convert a value from degrees to radians for the phase parameter, multiply it by $\frac{\pi}{180}$.

Applies to

See also