Mixed directional derivative
- Subject: Mixed directional derivative
- From: Olumide
- Date: Tue, 05 Aug 2008 06:48:21 +0100
Barton Willis wrote:
> Define a function grad:
>
> (%i4) grad(e,v) := makelist(diff(e,vk),vk,v)$
It worked, thanks a million. I made a slight change to f tho', and I've
been able to compute some really complex derivatives.
Examples:
depends (f, [x, y, z]);
grad(f, [x,y,z]).[vx, vy, vz];
grad( (grad(f, [x,y,z]).[vx, vy, vz]), [x, y, z] );
grad( (grad(f, [x,y,z]).[vx, vy, vz]), [x, y, z] ).[vx, vy, vz];
grad( ( grad( (grad(f, [x,y,z]).[vx, vy, vz]), [x, y, z] ).[vx, vy, vz]
) , [x,y,z] ).[ux,uy,uz]
grad( ( grad( ( grad( (grad(f, [x,y,z]).[vx, vy, vz]), [x, y, z] ).[vx,
vy, vz] ) , [x,y,z] ).[ux,uy,uz] ),[x,y,z] ).[ux,uy,uz]