Kai-Uwe Bux wrote:

> Olumide wrote:

>

>> I hope this isn't too trivial to ask, but I'm evaluating a polynomial

>> that involve lots of terms like x^2y^2z^3, and although I can use the

>> power function pow(a, b), I wonder if just writing x*x*y*y*z*z*z for

>> example wouldn't be more efficient than pow(x, 2)*pow(y, 2)*pow(z,3).

>> Or is it all the same?

>

> There is no way to tell a priory. You have to measure.

>

> However, if your polynomial has "lots of terms" like those, you might want

> to try the Horner scheme of evaluating polynomials:

>

> a_5 x^5 + a_4 x^4 + a_3 x^3 + a_2 x^2 + a_1 x^1 + a_0

>

> can be rewritten as

>

> ( ( ( ( a_5 * x + a_4 ) * x + a_3 ) * x + a_2 ) * x + a_1 ) * x + a_0

>

> which uses only 5 multiplications and 5 additions.

>

>

> Best

>

> Kai-Uwe Bux
Which is also an easy way to convert a string representation of a number

into the number itself

--

Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/>