05-15-2015, 08:26 PM

hi all,

my proposal for a function to calculate directional derivative ( \( \bigtriangledown f \cdot \overrightarrow{v} \) ).

It's a CAS program. Use: derivdir(f,v), where f is a function and v a vector.

I would like to thank Han for his hints in making this program.

Enjoy!

Salvo

my proposal for a function to calculate directional derivative ( \( \bigtriangledown f \cdot \overrightarrow{v} \) ).

It's a CAS program. Use: derivdir(f,v), where f is a function and v a vector.

I would like to thank Han for his hints in making this program.

Enjoy!

Salvo

Code:

#cas

// Directional derivative: dot(grad(f0), normalize(v))

derivdir(f,v):=

BEGIN

local g:=grad(f,[x,y,z]);

// gradient

local w:=normalize(v);

// versor

m:=dot(g,w);

// dot product

return m;

END;

#end