
# The adjoint differential of the logarithmic map base point

This function evaluates for $F(x)=\log_yx$ with fixed $y\in\M$ the adjoint differenital $D^*_xF(x)[\eta].$

It is calculated a corresponding adjoint Jacobi field AdjJacoiField. Since the weights are the same as for the differential DyLog, we refer to that page for details.

### Matlab Documentation

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%   nu = AdjDxLog(x,y,eta) - Adjoint of the Derivative of Log
%       with respect to the basis point x.
%   INPUT
%      x   : base point of the logarithm
%      y   : argument of the logarithm
%     eta  : (in TxM) direction to take the Adjoint derivative at.
%
%    OUTPUT
%     nu   : ( in TxM ) - the adjoint of DxLog with respect to eta
% ---
% MVIRT R. Bergmann, 2017-12-04