Re: [HP-Prime CAS] Vector Calculus Library Message #7 Posted by CompSystems on 30 Oct 2013, 11:24 p.m., in response to message #5 by Han
Han if I define my original function with diff, not fail, if define symbol d fail, is a possible BUG?
// step to step
f2(x,y,z):=x^3+y²+z; [ENTER]
[d(f2(x,y,z),x),d(f2(x,y,z),y),d(f2(x,y,z),z)] ; [ENTER] => [3*x²,2*y,1] // ok
[diff(f2(x,y,z),x) , diff(f2(x,y,z),y), diff(f2(x,y,z),z)]; [ENTER] => [3*x²,2*y,1] // ok
// define
gradient(f(x,y,z)):= [diff(f(x,y,z),x), diff(f(x,y,z),y), diff(f(x,y,z),z)]; [ENTER] Done
gradient(x^3+y²+z); [ENTER] => [3*x²,2*y,1] // ok
gradient(f(x,y,z)):= [d(f(x,y,z),x),d(f(x,y,z),y),d(f(x,y,z),z)]; [ENTER] Done
gradient(x^3+y²+z); [ENTER] => [0,0,0] ?? // BUG?
PD: on the entry line" another problem with v([1]) extraction of elements of a list, matrix ([m,n]), I can only be from an external editor (copy/paste) or encode in "algebraic" entry =(
sample
gradient2(f(x,y,z),v):=[diff(f(x,y,z),v([1])),diff(f(x,y,z),v([2])),diff(f(x,y,z),v([3]))];
Edited: 31 Oct 2013, 12:05 a.m.
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