We present a compact formula for the derivative of a 3-D rotation matrix with
respect to its exponential coordinates. A geometric interpretation of the
resulting expression is provided, as well as its agreement with other
less-compact but better-known formulas. To the best of our knowledge, this
simpler formula does not appear anywhere in the literature. We hope by
providing this more compact expression to alleviate the common pressure to
reluctantly resort to alternative representations in various computational
applications simply as a means to avoid the complexity of differential analysis
in exponential coordinates.Comment: 6 page
