Math.Atan2(Double, Double) Methode

Definition

Gibt einen Winkel zurück, dessen Tangens der Quotient zweier angegebener Zahlen ist.Returns the angle whose tangent is the quotient of two specified numbers.

public:
 static double Atan2(double y, double x);
public static double Atan2 (double y, double x);
static member Atan2 : double * double -> double
Public Shared Function Atan2 (y As Double, x As Double) As Double

Parameter

y
Double

Die y-Koordinate eines Punkts.The y coordinate of a point.

x
Double

Die x-Koordinate eines Punkts.The x coordinate of a point.

Gibt zurück

Ein Winkel (θ) im Bogenmaß im Bereich –π≤θ≤π, und tan(θ) = y / x, wobei (x, y) einen Punkt in der kartesischen Ebene darstellt.An angle, θ, measured in radians, such that -π≤θ≤π, and tan(θ) = y / x, where (x, y) is a point in the Cartesian plane. Beachten Sie dabei:Observe the following: – Wenn (x, y) im 1. Quadranten liegt, gilt 0 < θ < π/2.- For (x, y) in quadrant 1, 0 < θ < π/2.

– Wenn (x, y) im 2. Quadranten liegt, gilt π/2 < θ≤π.- For (x, y) in quadrant 2, π/2 < θ≤π.

– Wenn (x, y) im 3. Quadranten liegt, gilt –π < θ < –π/2.- For (x, y) in quadrant 3, -π < θ < -π/2.

– Wenn (x, y) im 4. Quadranten liegt, gilt –π/2 < θ < 0.- For (x, y) in quadrant 4, -π/2 < θ < 0.

Für Punkte an den Begrenzungen der Quadranten wird der folgende Rückgabewert zurückgegeben:For points on the boundaries of the quadrants, the return value is the following: – Wenn y gleich 0 und x nicht negativ ist, gilt θ = 0.- If y is 0 and x is not negative, θ = 0.

– Wenn y gleich 0 und x negativ ist, gilt θ = π.- If y is 0 and x is negative, θ = π.

– Wenn y positiv und x gleich 0 ist, gilt θ = π/2.- If y is positive and x is 0, θ = π/2.

– Wenn y negativ ist und x gleich 0 ist, gilt θ = -π/2.- If y is negative and x is 0, θ = -π/2.

– Wenn y gleich 0 ist und x gleich 0 ist, gilt θ = 0.- If y is 0 and x is 0, θ = 0.

Wenn x oder y gleich NaN ist oder wenn x und y entweder gleich PositiveInfinity oder gleich NegativeInfinity sind, gibt die Methode NaN zurück.If x or y is NaN, or if x and y are either PositiveInfinity or NegativeInfinity, the method returns NaN.

Beispiele

Im folgenden Beispiel wird veranschaulicht, wie der Arkus Tangens eines Winkels und eines Vektors berechnet wird.The following example demonstrates how to calculate the arctangent of an angle and a vector. Der resultierende Wert wird in der-Konsole angezeigt.The resulting value is displayed in the console.

// This example demonstrates Math.Atan()
//                           Math.Atan2()
//                           Math.Tan()
using namespace System;
int main()
{
   double x = 1.0;
   double y = 2.0;
   double angle;
   double radians;
   double result;
   
   // Calculate the tangent of 30 degrees.
   angle = 30;
   radians = angle * (Math::PI / 180);
   result = Math::Tan( radians );
   Console::WriteLine( "The tangent of 30 degrees is {0}.", result );
   
   // Calculate the arctangent of the previous tangent.
   radians = Math::Atan( result );
   angle = radians * (180 / Math::PI);
   Console::WriteLine( "The previous tangent is equivalent to {0} degrees.", angle );
   
   // Calculate the arctangent of an angle.
   String^ line1 = "{0}The arctangent of the angle formed by the x-axis and ";
   String^ line2 = "a vector to point ({0},{1}) is {2}, ";
   String^ line3 = "which is equivalent to {0} degrees.";
   radians = Math::Atan2( y, x );
   angle = radians * (180 / Math::PI);
   Console::WriteLine( line1, Environment::NewLine );
   Console::WriteLine( line2, x, y, radians );
   Console::WriteLine( line3, angle );
}

/*
This example produces the following results:

The tangent of 30 degrees is 0.577350269189626.
The previous tangent is equivalent to 30 degrees.

The arctangent of the angle formed by the x-axis and
a vector to point (1,2) is 1.10714871779409,
which is equivalent to 63.434948822922 degrees.
*/
// This example demonstrates Math.Atan()
//                           Math.Atan2()
//                           Math.Tan()
using System;

class Sample 
{
    public static void Main() 
    {
    double x = 1.0;
    double y = 2.0;
    double angle;
    double radians;
    double result;

// Calculate the tangent of 30 degrees.
    angle = 30;
    radians = angle * (Math.PI/180);
    result = Math.Tan(radians);
    Console.WriteLine("The tangent of 30 degrees is {0}.", result);

// Calculate the arctangent of the previous tangent.
    radians = Math.Atan(result);
    angle = radians * (180/Math.PI);
    Console.WriteLine("The previous tangent is equivalent to {0} degrees.", angle);

// Calculate the arctangent of an angle.
    String line1 = "{0}The arctangent of the angle formed by the x-axis and ";
    String line2 = "a vector to point ({0},{1}) is {2}, ";
    String line3 = "which is equivalent to {0} degrees.";

    radians = Math.Atan2(y, x);
    angle = radians * (180/Math.PI);

    Console.WriteLine(line1, Environment.NewLine);
    Console.WriteLine(line2, x, y, radians);
    Console.WriteLine(line3, angle);
    }
}
/*
This example produces the following results:

The tangent of 30 degrees is 0.577350269189626.
The previous tangent is equivalent to 30 degrees.

The arctangent of the angle formed by the x-axis and
a vector to point (1,2) is 1.10714871779409,
which is equivalent to 63.434948822922 degrees.
*/
' This example demonstrates Math.Atan()
'                           Math.Atan2()
'                           Math.Tan()
Class Sample
   Public Shared Sub Main()
      Dim x As Double = 1.0
      Dim y As Double = 2.0
      Dim angle As Double
      Dim radians As Double
      Dim result As Double
      
      ' Calculate the tangent of 30 degrees.
      angle = 30
      radians = angle *(Math.PI / 180)
      result = Math.Tan(radians)
      Console.WriteLine("The tangent of 30 degrees is {0}.", result)
      
      ' Calculate the arctangent of the previous tangent.
      radians = Math.Atan(result)
      angle = radians *(180 / Math.PI)
      Console.WriteLine("The previous tangent is equivalent to {0} degrees.", angle)
      
      ' Calculate the arctangent of an angle.
      Dim line1 As [String] = "{0}The arctangent of the angle formed by the x-axis and "
      Dim line2 As [String] = "a vector to point ({0},{1}) is {2}, "
      Dim line3 As [String] = "which is equivalent to {0} degrees."
      
      radians = Math.Atan2(y, x)
      angle = radians *(180 / Math.PI)
      
      Console.WriteLine(line1, Environment.NewLine)
      Console.WriteLine(line2, x, y, radians)
      Console.WriteLine(line3, angle)
   End Sub
End Class
'
'This example produces the following results:
'
'The tangent of 30 degrees is 0.577350269189626.
'The previous tangent is equivalent to 30 degrees.
'
'The arctangent of the angle formed by the x-axis and
'a vector to point (1,2) is 1.10714871779409,
'which is equivalent to 63.434948822922 degrees.
'

Hinweise

Der Rückgabewert ist der Winkel in der kartesischen Ebene, der durch die x-Achse gebildet wird, und ein Vektor, der mit dem Ursprung beginnt (0,0) und am Punkt endet (x, y).The return value is the angle in the Cartesian plane formed by the x-axis, and a vector starting from the origin, (0,0), and terminating at the point, (x,y).

Gilt für: