On 9/7/2009 1:18:32 PM, leyo123 wrote:
>Hi,
>In the attached Mtahcad
>sheet,I have an equation for
>Vc_se(A_dB).
>I have evaluated this
>equation symbolically.
>How to express Vc_se(A_dB) as
>5 th or 6 th degree polynomial
>with A_dB as independent
>variable?
>Thanks
_______________________________
You can replace Se(x) by any order poly. That does not help yet as you have to expand X^Y. The function is "NOT of polynomial format", thus excluding the simple polynomial. The "polynomial" must be a rational fraction or of a different form "Cheby". "Cheby", you have ... try an order 9 to make it equivalent to the 5/4 rational given. Now, Cheby will be 2� times slower than the rational.
Apparently, the 3 responders have interpreted same: you have a function, out of the blue, that you want to plug in a firmware. I have assumed the firmware can +, -, *, / ,,, thus proposed the hyperfast very accurate rational. It could be that the function is ExpDecay3, but can't tell has you have not provided the original data set, neither the design of this function. What I mean here is that at the point of I(x), the project may still be "band aid".
Taking your I(x) function, R� of ExpDecay3 = 0.99999. The series expansion of the ExpDecay3 is dramatic with an error of 10^14 at 50 !!! A firmware that won't +, -, *, / is back to the dark age before Pascal, and what about: fixed /floating point arithmetic, accuracy like 1.123456789*1 = 1.23 or 1.23456789 ???
All for you to cogitate.
jmG