Symbolic Math Toolbox VS MuPAD: example in advance of the first?

MATLAB

>> simplify(exp(log10(x)))
ans =
x^(1/log(10))

MuPAD

simplify(exp(log(10,x)), ln)

No effect. How to force MuPAD to simplify truely? I used consider MATLAB Simb.Tbx as a reduced version of MuPAD? That is -- MATLAB calls the MuPAD functions...

Answer 1

[Walter Roberson]

This is as documented here

Mathematically, log(b, b^y) = y holds true for any real y. This simplification is implemented for the following cases:  i) b is a symbolic (indexed) identifier and y is of type Type::Real,  ii) b is numerical and y is integer or rational.

and

Note that arithmetical rules such as log(b, x*y) = log(b, x) + log(b, y) are not valid throughout the complex plane. Use properties to mark identifiers as real and apply functions such as expand or simplify to manipulate expressions involving log. Cf. example 4.

So you could possibly use

simplify(exp(log(10,x))) assuming x::real

[Walter Roberson]

Might have to be x::Real perhaps, instead of x::real

[Igor]

Clearly.

But Log of complex value may be account like sin() with periodic term.

Thanks.

Answer 2

[Paulo Silva]

syms x
simplify(exp(log10(x)))

[Igor]

No, no :)

MATLAB works validly, you haven't seen ANS

Problem in MuPAD

Answer 3

[Andrei Bobrov]

in MuPAD

expand(subs(exp(log(10,x)),log(10,x)=ln(x)/ln(10)));

EDIT

rewrite(exp(log(10,x)),ln)

[Igor]

the last better..

thanks