Error in using "vary"

Question

Hi,

I found a couple of errors in the command vary:

ex1:= \log(A);
vary(_, $A -> \delta{A}$);

,

ex2:= \ln(A);
vary(_, $A -> \delta{A}$);

, and

ex3:= \sin(A);
vary(_, $A -> \delta{A}$);

. The first and second codes yields nothing. The last one causes the kernel crash. If I made just a stupid mistake in writing a code, please let me know. Thanks.

Best wishes, Yuta

P.S. Kasper, I posted the above in this forum just in case. Sorry if you already kept them in mind.

Comments

It seems that the Cadabra doesn't know about the properties of the these predefined functions.

Answer 1

In order to implement this right I need to think a bit more: what you want to do really is the domain of a scalar computer algebra system, so I would like to not re-invent the wheel but instead let Sympy do this behind the scenes (even for more complicated expressions). For the time being (the version on github now) I have made this spit out an error so you at least do not get a crash or a nonsense answer. It's on my todo list.