theta

Convert transformation or rotation to 2-D rotation angle

Since R2023b

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    Syntax

    angle = theta(transformation)
    angle = theta(rotation)

    Description

    angle = theta(transformation) extracts the 2-D rotation angle angle from the transformation transformation.

    example

    angle = theta(rotation) extracts the 2-D rotation angle angle from the rotation rotation.

    example

    Examples

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    Open Live Script

    Create SE(2) transformation with a rotation defined by an angle pi/2.

    angle1 = pi/2
    angle1 = 
1.5708

    T = se2(angle1,"theta")
    T = se2
    0.0000   -1.0000         0
    1.0000    0.0000         0
         0         0    1.0000

    Get the rotation angle from the transformation.

    angle2 = theta(T)
    angle2 = 
1.5708
    Open Live Script

    Create SO(2) rotation defined by an angle pi/2.

    angle1 = pi/2
    angle1 = 
1.5708

    R = so2(angle1,"theta")
    R = so2
    0.0000   -1.0000
    1.0000    0.0000

    Get the rotation angle from the rotation.

    angle2 = theta(R)
    angle2 = 
1.5708

    Input Arguments

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    Transformation, specified as an se2 object or as an N-by-M array of se2 objects. N is the total number of transformations.

    If transformation is a N-by-M array, the angle argument is the same size and contains an angle for each of the se2 objects specified in the array.

    Data Types: single | double

    Rotation, specified as an so2 object or as an N-by-M array of so2 objects. N is the total number of rotations.

    If rotation is a N-by-M array, the angle argument is the same size and contains an angle for each of the so2 objects specified in the array.

    Output Arguments

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    Rotation angle, returned as a numeric scalar for a scalar input and as an N-by-M matrix for an array input. N and M are the dimensions of the input rotation or transformation argument. Each element of the matrix is an angle, in radians, and each angle corresponds to a rotation or transformation in the input at the same index location.

    The rotation angle is counterclockwise positive when you look along the axis toward the origin.

    Data Types: single | double

    Version History

    Introduced in R2023b

    See Also

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