On Sunday, 17 February 2019 18:46:48 UTC+1, Martin R wrote: > > Hi Kurt! > > I'm not sure I understand the problem. With the patch applied, I obtain: >
You do, your patch is certainly a partial solution (now G and h are correct). What I actually wanted to say/ask is that/whether g and G ought to be identical. Semantically g(x,y)=D(f(x,y), x) => g(x,x)=D(f(x,x), x), but is that really the answer the user expects? It might be a source of confusion. If you hadn't pointed out the issue, I certainly would have made the mistake using g instead of G ;) What is the general opinion? BTW thanks for the patch. Kurt > > (1) -> f:=operator 'f > > (1) f > Type: > BasicOperator > (2) -> g(x,y) == D(f(x,y), x) > Type: > Void > (3) -> G(x,y) == eval(D(f(t,s), t),[t=x,s=y]) > Type: > Void > (4) -> expr:=D(f(x,y), x, 1); > > Type: > Expression(Integer) > (5) -> function(expr, h, [x,y]); > > Type: > Symbol > (6) -> [G(x,x), g(x,x), h(x,x)] > > (6) [f (x,x), f (x,x) + f (x,x), f (x,x)] > ,1 ,2 ,1 ,1 > Type: > List(Expression(Integer)) > > (7) -> [interpret(G(x,x)::INFORM), interpret(g(x,x)::INFORM), > interpret(h(x,x)::INFORM)] > > (7) [f (x,x), f (x,x) + f (x,x), f (x,x)] > ,1 ,2 ,1 ,1 > Type: > List(Any) > > > I think that this is OK, let's look at it in detail. > > * G(x,y) == eval(D(f(t,s), t),[t=x,s=y]) > > D(f(t,s), t) means "consider f as a bivariate function and compute the > derivative with respect to the first variable" > G then evaluates this expression at t=x and s=x. > > * g(x,y) == D(f(x,y), x) > > g(x,x) means "compute D(f(x,x), x)" > > * function(expr, h, [x,y]) > > I admit that I am not completely sure about the semantics of "function", > but I think it should be roughly equivalent to G. > > Maybe you could say what result you would expect? > > Best wishes, > > Martin > -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to fricas-devel+unsubscr...@googlegroups.com. To post to this group, send email to fricas-devel@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/fricas-devel/c4c0c8d5-97a9-4e5f-a1ba-52d0e4e5a5f3%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
