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value of alpha1[celli] is not correct

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Old   May 27, 2014, 12:32
Default value of alpha1[celli] is not correct
  #1
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jaming
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Hi Foamers,
I have a problem setting in the forAll() loop the right condition:
##########################
forAll(alpha1,celli)
{
if (alpha1[celli] > 1 )
{

Pout<<"alpha1= "<<alpha1[celli]<<endl;
}
}

##########################

I also get

alpha1= 1

in the results what I think is not logic.

So if someone has any idea I will be thankful
Yamine
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Old   May 27, 2014, 14:34
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ngj
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Niels Gjoel Jacobsen
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Hallo,

It is probably related to your write precision in your controlDict, e.g. if the write precision is 6, then 1.000000007 is written as 1.

You could test this by using the following code:

Code:
Pout << alpha1[celli] << tab << 1 - alpha1[celli] << endl;
Kind regards,

Niels
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Old   May 27, 2014, 16:01
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jaming
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Many thanks for you quick replay,
but look for example hier:

Code:
forAll(alpha1, celli)
    {
     if ( alpha1[celli] < scalar(1.))
       {
    
         Pout<< "Alpha1=  "<<alpha1[celli]<< endl;
       }
I get the flow:
PHP Code:
...........   ..................
Alpha1=  0.0144193383
Alpha1
=  0.9575155878
Alpha1
=  1
Alpha1
=  0.1574193345
Alpha1
=  5.502415325e-11
Alpha1
=  5.162033835e-11
Alpha1
=  8.173407791e-13
...........    ....................... 
The idea is to set some conditions with alpha1 but I found that alpha1[celli] didn't pass the wished value at all.
And like you can see unfortunately 1 is not filtered here

With kind regards,
Yamine
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Old   May 27, 2014, 16:13
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  #4
ngj
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Niels Gjoel Jacobsen
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With your recent code, you turned around the inequality, and the value being 1, can actually be 0.9999999999, i.e. to me the code still does the rigth thing.

Kind regards,

Niels
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Old   May 27, 2014, 16:36
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jaming
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Hi ngj

Many Thanks for your unpayable help.

Regards
Yamine
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