>
> maybe if there is a function which shows the explicit and implicit
> dependencies, I can write my own partialdiff function.
# I found that "dependencies" lists all dependencies. In my case:
dependencies;
(%i21) dependencies;
(%o21) [V(x), x(t)]
(%i22)
# I thought that for a function which will be called such that:
partialdiff(function, variable);
# I can look at all elements of this array and if there is an element, f(x),
of which f=function and x=variable, then take the derivative, because f
depends x explicitly, but if no such element found then give 0.
# I tried to implement this idea:
partialdiff(fun, var):=
block([dep,N,depexp], depexp: false, dep: dependencies, N: length(dep),
(for i:1 step 1 while i<=N
do if (part(dep[i],0) = fun) and (part(dep[i],1)=var) then
depexp:true),
if depexp then diff(fun,var) else 0);
# Which gives:
(%i19) partialdiff(V,t);
dV
(%o19) --
dx
(%i20) partialdiff(V,t);
(%o20) 0
# This is my solution, which needs explicit definitions of dependencies
before hand. But I am not sure if it can handle another cases.
-u?ur-