CFD Online Discussion Forums - How to go through every element of a field?

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)

- OpenFOAM Programming & Development (https://www.cfd-online.com/Forums/openfoam-programming-development/)

- - How to go through every element of a field? (https://www.cfd-online.com/Forums/openfoam-programming-development/169659-how-go-through-every-element-field.html)

How to go through every element of a field?

Hello Dear Foamers~!

In my project i want to define a complex source field. For example, I want solve the equation:

Code:

volScalarField p;

volScalarField sourceField;

solve( fvm::laplacian( p ) == sourceField )

Furthermore, the source filed is a complex space function, for example, such as

Quote:

f(x, y, z) = sin(x) * cos(y) * z

Here is my though about this problem:
1. one field of every cell center's position must be obtained, that can be achieved by:

Code:

volVectorField centerPostions = mesh.C();

2. there must be a method in order to read through every element of the field. such as:

Code:

for(i = first_element_index, i <= last_element_index, i++)

{

     sourceField.element(i) = sin( centerPosition.element(i).x() ) * .....

}

I was blocked in the second step, dear foamers, is there a method can accomplish that?
I am open for every advices!
Thanks very much!

One possible way?

As every field can be seen as UList<Type>, so it comes to me that if method inside the class template can help.

You are looking "forAll" (search the forum for this keyword).

Problem almost solved!

Thank you very much for your response!
After searching and studying the threads of the forum with key word "forAll". I have got the basic understanding of the macro "forAll". What's more, I have developed my own "manual" method in order to scan a field:

Code:

    Foam::vector * i;

    Foam::label j = 0;

    volVectorField position = mesh.C();



    Info << "\n the first method of scanning the field " << endl;

    for ( i = position.begin(); i <= position.end(); i++) {

      Info << "\n the cell " << j << "'s position is " << position[j] << endl;

      j++;

      if (j == 5) {

        break;

      }

    }



    Info<< "\n the second method of scanning the field " << endl;

    j = 0;

    forAll( position, elmtID ){

      Info << "\n the cell " << elmtID << "'s position is " << position[elmtID] << endl;

      j++;

      if (j == 5) {

        break;

      }

    }

and the result is quite well::):D

Quote:

the first method of scanning the field

the cell 0's position is (1.25e-05 0.000125 0.0001)

the cell 1's position is (3.75e-05 0.000125 0.0001)

the cell 2's position is (6.25e-05 0.000125 0.0001)

the cell 3's position is (8.75e-05 0.000125 0.0001)

the cell 4's position is (0.0001125 0.000125 0.0001)

the second method of scanning the field

the cell 0's position is (1.25e-05 0.000125 0.0001)

the cell 1's position is (3.75e-05 0.000125 0.0001)

the cell 2's position is (6.25e-05 0.000125 0.0001)

the cell 3's position is (8.75e-05 0.000125 0.0001)

the cell 4's position is (0.0001125 0.000125 0.0001)

Quote:

Originally Posted by akidess (Post 595160)

You are looking "forAll" (search the forum for this keyword).