Oscar Alvarez
Oscar Alvarez

Reputation: 69

Taking Derivative of a Matrix with functions in Maple. Want to leave functions as prime (f' or f'') and not evaluate

I want to evaluate a matrix that has a function named alpha. When I take the derivative of alpha, I would like the result to give me an alpha'

Example: if I have sin(alpha) I want to get cos(alpha)alpha' but throughout the matrix.

Upvotes: 0

Views: 454

Answers (2)

Oscar Alvarez
Oscar Alvarez

Reputation: 69

Thank you for answering. I found the solution after a lot of guess and checking and reading. Here is my code with my solution.

with(Typesetting)  : 
Settings(typesetdot = true);

a:= alpha(t)

Rna:= [ cos(alpha), -sin(alpha), 0; sin(alpha), cos(alpha), 0; 0, 0, 1 ]

b := beta(t)

Rab:= [ cos(beta), -sin(beta), 0; sin(beta), cos(beta), 0; 0, 0, 1 ]

Rnab:= Rna . Rab

Rnab:= map(diff, Rnab, t)

Sorry for the multiple answers, I am getting use to the website.

Upvotes: 1

acer
acer

Reputation: 7271

It is quite unclear what you mean by stating that you have a "function" in Maple, of which you intend to take the derivative.

That could mean some expression depending upon a name such as t, with respect to which you intend on differentiating using Maple's diff command. And such an expression may be assigned to alpha, or it may contain the function call alpha(t).

Or perhaps you wish to treat alpha as an operator name, and differentiate functionally with Maple's D command.

I shall make a guess as to what you meant.

restart;
Typesetting:-Suppress(alpha(t));
Typesetting:-Settings(prime=t):
Typesetting:-Settings(typesetprime=true):

M := Matrix([[ sin(alpha(t)), exp(p*alpha(t)) ]]);

map(diff, M, t);

If that's not the kind of thing that you're after then you should explain your purpose and needs in greater detail.

Your question's title mentions a desire to have something not "evaluate". What did you mean by that? Have you perhaps assigned something to the name f?

Upvotes: 1

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