Excel formula problem
Excel formula problem
(OP)
Hi i have problem with a formula in excel. It goes like:
=((KVROD((4*(C12^2))/(PI()^4)-((4*C12*(C8^3))/(27*(PI()^2))))-(C8^3/27)+(2*C12/(PI()^2)))^(1/3))-(C8/3)+((C8^2)/(9*((KVROD((4*C12^2)/(PI()^4)-((4*C12*C8^3)/(27*(PI()^2))))-(C8^3/27)+(2*C12/(PI()^2)))^(1/3))))
In mathcad it looks like this:

where; V is G12 and d is C8.
I got the formula working in mathcad, and have to do the same in excel. Can somebody show me a solution? I fear it something with complex numbers to do
Please help
=((KVROD((4*(C12^2))/(PI()^4)-((4*C12*(C8^3))/(27*(PI()^2))))-(C8^3/27)+(2*C12/(PI()^2)))^(1/3))-(C8/3)+((C8^2)/(9*((KVROD((4*C12^2)/(PI()^4)-((4*C12*C8^3)/(27*(PI()^2))))-(C8^3/27)+(2*C12/(PI()^2)))^(1/3))))
In mathcad it looks like this:

where; V is G12 and d is C8.
I got the formula working in mathcad, and have to do the same in excel. Can somebody show me a solution? I fear it something with complex numbers to do
Please help





RE: Excel formula problem
2 - what is kvrod?
3 - good luck. Just need to do the grunt work to check everything carefully. If needed break the formula into smaller parts and see if they give the required results.
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RE: Excel formula problem
3 - good luck. You just need to do the grunt work to check everything carefully. If needed break the formula into smaller parts and see if they give the required results.
=====================================
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RE: Excel formula problem
Another thing that I've had help is to break the equation up into smaller chunks and then at the end I can combine the chunks with considerably fewer parenthesis (I started to try to match your parenthesis but I got lost).
David
RE: Excel formula problem
For at least some values of V and d, the terms within the square root can yield a negative number, so that the whole square root term is a complex number. Mathcad seems to be able to handle this in its stride, and the complex terms seem to cancel out so that the total solution seems to yield a real number (at least for the few simple examples I have tried). Excel "chokes" when you try to evaluate the square root of a complex number, however.
You might have some success if you use the "IMSQRT" (complex square root) function instead of "SQRT". (You need to install the "Analysis ToolPak" Add-In to have access to complex functions in Excel.)
Hope this helps!
RE: Excel formula problem
It is probably a matter of taste, but for those who find it easier to work with the minimum amount of brackets your formula can be reduced to
=(KVROD(4* C12^2/PI()^4-4*C12*C8^3/(27*PI()^2))-C8^3/27+2*C12/ PI()^2)^(1/3)-C8/3+C8^2/(9*(KVROD(4*C12^2/PI()^4-4*C12*C8^3/(27*PI()^2))-C8^3/27+2*C12/ PI()^2)^(1/3))
RE: Excel formula problem
Best regards
Morten
RE: Excel formula problem
http://www.excelcalcs.com/
RE: Excel formula problem
d <= 3*(V/pi^2)^(1/3)
RE: Excel formula problem
RE: Excel formula problem
If C12 is the value in column C, row 12, , then let v = C12
Similarly, let d = C8.
Now prepare the equation using those values directly.
Check each component and the first answer .
RE: Excel formula problem
This may be helpful: an up-to-date dictionary for Excel 2007 functions with 14 languages:
htt
Cheers,
Joerd
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RE: Excel formula problem
Best regards
Morten
RE: Excel formula problem
RE: Excel formula problem
http://www.engineering-4e.com