Directional Derivative - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: HP Prime (/forum-5.html) +--- Thread: Directional Derivative (/thread-2959.html) |
Directional Derivative - salvomic - 01-29-2015 12:17 PM hi all, would like anybody to help me to get a program for Directional Derivative? Starting with this: it's the dot product between Gradient of v and person of u, ( {tex} \( \bigtriangledown f \cdot \overrightarrow{v} \) {/tex} ) so dot (grad(u) , v/normalize(v)) could be good, but if use it with "Define" it doesn't works, as "dot" (lowercase) is always changed in "DOT" (uppercase) and the function gives error "dot vector Error: bad argument value"... (I'm using CAS) Thank you in advance! Salvo RE: Directional Derivative - salvomic - 01-29-2015 04:36 PM I'm trying this program: Code:
It seems to works with f as a function (expression), f(0), like (x^2-x*y) and v as vector (also not normalized), like [3,4] or [x,3y]; the program first normalize the vector finding its versor, and then return the symbolic directional derivative in the direction of that vector... Any help to make it better? There is a way to have the function listed in the Toolbox -> User? Thank you :-) salvo RE: Directional Derivative - Han - 01-29-2015 06:57 PM (01-29-2015 04:36 PM)salvomic Wrote: There is a way to have the function listed in the Toolbox -> User? Make a non-CAS wrapper. DDER(f,v) BEGIN derivdir(f,v); END; Since DDER is a non-CAS program, you would then have to enter your arguments as strings: DDER("x^2*y+z","[3,4,1]"); RE: Directional Derivative - salvomic - 01-29-2015 07:08 PM (01-29-2015 06:57 PM)Han Wrote: Make a non-CAS wrapper. I'll try, thank you Han! |