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error 6194: power function

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Hi,

I have got a error (6194)

the error said: attempt to evaluate non-integral power of negative number
-function: power

failed to evaluate variable

whether someone know how to solve this problem? Comsol does not allow the non-integral power of negative number?

Thanks!

Xin

2 Replies Last Post Dec 26, 2009, 10:43 AM EST
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Hello Xin Jin

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Posted: 9 years ago Dec 26, 2009, 10:43 AM EST
OOps double posting
Sorry
OOps double posting Sorry

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Posted: 9 years ago Dec 26, 2009, 10:43 AM EST
Hello ,
pretty new to comsol,
i get the error 6194 in a context i dont understand..(seethe full error message below)

as you will see I use the operator abs before a square root operator [ with an extra non necessary parenthesis I added in the process] but I get tthe power of negative error...
If I remove the square root the problem disappear so it is clearly aassociated with it..
and the term under the square root is abs( expression). exactely as recommended in comsol manual...
any idea on what is going on?
Thanks in advance
JF


Exception:
com.femlab.jni.FlNativeException: Failed to evaluate expression
Messages:
Failed to evaluate expression
- Expression: d(d(((-px*test(px)-(Llamf+Lturbf)*test(p))-(pt*test(p)))*(dvol_ale),{test@5}),x)

Failed to evaluate symbolic derivative variable
- Variable: Lturbf@VDN$x
- Defined as: ((1/wf)*(((2*u1d)*(((-(dflc2hs((x_fluid_front-x),(0.0010000000000000000208*x_fluid_front))/(0.0010000000000000000208*x_fluid_front)))*u)))*((abs((eps_frac/wf))^0.5)*(0.10000000000000000555*rhof))))

Power of negative
- Function: ^

Stack trace:
at evaltree.cpp, row 866, ()
at evalnodes.cpp, row 1082, ()
at evalfun_binary.cpp, row 1184, ()
at com.femlab.solver.FlSolver.femTime(Native Method)
at com.femlab.solver.FemTime.run(Unknown Source)
at com.femlab.server.FlRunner.run(Unknown Source)
at com.femlab.util.i.run(Unknown Source)
at com.femlab.util.aa.run(Unknown Source)
Hello , pretty new to comsol, i get the error 6194 in a context i dont understand..(seethe full error message below) as you will see I use the operator abs before a square root operator [ with an extra non necessary parenthesis I added in the process] but I get tthe power of negative error... If I remove the square root the problem disappear so it is clearly aassociated with it.. and the term under the square root is abs( expression). exactely as recommended in comsol manual... any idea on what is going on? Thanks in advance JF Exception: com.femlab.jni.FlNativeException: Failed to evaluate expression Messages: Failed to evaluate expression - Expression: d(d(((-px*test(px)-(Llamf+Lturbf)*test(p))-(pt*test(p)))*(dvol_ale),{test@5}),x) Failed to evaluate symbolic derivative variable - Variable: Lturbf@VDN$x - Defined as: ((1/wf)*(((2*u1d)*(((-(dflc2hs((x_fluid_front-x),(0.0010000000000000000208*x_fluid_front))/(0.0010000000000000000208*x_fluid_front)))*u)))*((abs((eps_frac/wf))^0.5)*(0.10000000000000000555*rhof)))) Power of negative - Function: ^ Stack trace: at evaltree.cpp, row 866, () at evalnodes.cpp, row 1082, () at evalfun_binary.cpp, row 1184, () at com.femlab.solver.FlSolver.femTime(Native Method) at com.femlab.solver.FemTime.run(Unknown Source) at com.femlab.server.FlRunner.run(Unknown Source) at com.femlab.util.i.run(Unknown Source) at com.femlab.util.aa.run(Unknown Source)

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