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Error in If-else statement

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Old   December 8, 2016, 08:59
Default Error in If-else statement
  #1
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fluidflowsteel
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Hi all, i have the following problem

VolscalarField X

VolscalarField Y

VolscalarField theta

theta = atan(Y/X)


We know that for theta = pi/2 or (3*pi)/2 etc. tangent values are undefined.

Based on the X and Y coordinates of a point, I need to find out the angle theta in radians in OpenFOAM 3.0

I have written the following code which compiled without any errors


forAll(X, cellI)
{
forAll(Y, cellI)
{
forAll(Theta, cellI)
{
if (X[cellI] == scalar(0.0))
{
if (Y[cellI] > scalar(0.0))
{
Theta = (Foam::constant::mathematical:i*0.5);
}
else
{
Theta = -(Foam::constant::mathematical:i*0.5);
}
}
else if (X[cellI] > scalar(0.0))
{
if (Y[cellI] > scalar(0.0))
{
Theta = atan(Y/X);
}
else
{
Theta = (Foam::constant::mathematical:i*2) + atan(Y/X);
}
}
else
{
Theta = (Foam::constant::mathematical:i) + atan(Y/X);
}
}
}
}


It has compiled without any errors while running it is giving the following error. Seems to be related to something kind of 0/0 ?

Can anyone help me ?

Calculating scalar transport

Courant Number mean: 0 max: 0
Time = 1e-12

#0 Foam::error:rintStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 ? in "/lib/x86_64-linux-gnu/libc.so.6"
#3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) at ??:?
#4 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam:perator/<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#5 ? at ??:?
#6 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#7 ? at ??:?


Thanks in advance

With regards
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Old   December 9, 2016, 07:23
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  #2
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khedar
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I would add a bunch of "Info" statements to pinpoint where "something/0" is occuring and then try to correct/modify it.
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Old   December 9, 2016, 07:46
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fluidflowsteel
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Thanks for your input. Just found the function Foam::atan2(x,y) to calculate the angle theta (which can lie in any of the four quadrants) directly instead of if-else statements (the way i wrote the code in the thread). but in my case x and y are the volume scalar field. will it be like Theta = atan2f(x,y) ?
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