Inverse tangent.
(Quaternion overloading of standard MATLAB® function)
Y = atan(X)
atan(X) computes the inverse tangent of its argument, which must be a real quaternion (atan is not yet implemented for complexified quaternions).
This function is computed using the Matlab® function of the same name by first computing an isomorphic complex number. The result is then assigned the same quaternion axis as the original argument.
>> atan(qi + qj + qk) ans = 1.571 + 0.3802 * I + 0.3802 * J + 0.3802 * K