Where can I find the function description for the gradient while finding the critic gradient or the actor gradient used in RL DDPG agent? When I open gradient by right clicking on it , I get the Numerical gradient help file, Is this the correct one? What does the text 'output-input' mean when the dQdInput is taken in the next line of the code.
I want to use the gradient function for my custom agent.
criticGradient = gradient(this.Critic,'loss-parameters',...
[Observations, Actions], targetq);
dQdInput=gradient(obj.Critic,'output-input',[Observations,Actions]);