Thanks for that. I've just discovered that "depends" works:
depends(y,x);
depends(f,[x,y]);
diff(f,x);
Alasdair
On Sat, Jun 1, 2013 at 1:49 AM, Leo Butler
<l_butler at users.sourceforge.net>wrote:
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> Something similar may have been asked before, but anyway... is there a
> way
> to coerce Maxima to differentiate, say f(x,y(x)) with respect to x, and
> produce
>
> D(f)(x) + f.D(f)(y) ?
>
> Or to differentiate f(y(x)) and produce
>
> D(f)(y).D(y)(x) ?
>
> Thanks.
>
> Option 1.
> load('pdiff);
>
> Option 2.
> Use diff and subst:
>
> subst([del(x)=1, del(y)='diff(y,x)], diff(f(x,y)));
>
> Leo
>
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