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UtilsConvertEllipseElevationAngleToPhaseAngle Method

Converts the elevation angle eta of the ellipse with semi axes a and b, the orientation angle phi into the phase angle theta.

Namespace: RAYLASE.Marker.VectorGraphicElement
Assembly: RAYLASE.Marker.VectorGraphicElement (in RAYLASE.Marker.VectorGraphicElement.dll) Version: 2.19.0
Syntax
C#
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public static double ConvertEllipseElevationAngleToPhaseAngle(
	double a,
	double b,
	double phi,
	double eta,
	bool isRad
)

Parameters

a  Double
semiaxis a of the ellipse
b  Double
semiaxis b of the ellipse
phi  Double
orientation angle of the ellipse
eta  Double
elevation angle of a point on the ellipse
isRad  Boolean
if false, the angle is converted into deg and the result is returned in deg as well

Return Value

Double
the phase angle theta to get the same point on the ellipse as under the elevation angle eta.
Remarks
theta is the angle to put into the ellipse equations to get the same point on the ellipse. For the definitions see the first sketch in ConvertEllipsePhaseAngleToElevationAngle(Double, Double, Double, Boolean). To take the orientation angle into account the general equations of the ellipse's coordinates are used:
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x = a*cos(theta)*cos(phi) - b*sin(theta)*sin(phi)
y = a*cos(theta)*sin(phi) + b*sin(theta)*cos(phi)
The elevation angle eta is atan(y/x). Solving the equation tan(eta) = y/x for tan(theta) leads to
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             a*tan(eta)*cos(phi)-a*sin(phi)
tan(theta) = ------------------------------
             b*(tan(eta)*sin(phi)+cos(phi))
See Also