Mat2Q:
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Converts a transformation matrix to a quaternion.
Does not check to see that m is orthonormal.
Since version 1.
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Form:
q = Mat2Q ( m )
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Inputs
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m (3,3) Orthonormal transformation matrix
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Outputs
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q (4,1) Equivalent quaternion
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References: Shepperd, S. W., Quaternion from Rotation Matrix,
J. Guidance, Vol. 1, No. 3, May-June, 1978, pp. 223-224.
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