[sega]

Hello World.

I'm currently trying to understand the check for a correct local coordinate system with the use of timeVaryingMappedFixedValue boundary condition.

For simplicity I will post the relevant part of the code.
The complete code is here: http://foam.sourceforge.net/doc/Doxy...8C_source.html

    const point& p0 = samplePoints[0];

    // Find point separate from p0
    vector e1;
    label index1 = -1;

    for (label i = 1; i < samplePoints.size(); i++)
    {
        e1 = samplePoints[i] - p0;

        scalar magE1 = mag(e1);

        if (magE1 > SMALL)
        {
            e1 /= magE1;
            index1 = i;
            break;
        }
    }

    // Find point that makes angle with n1
    label index2 = -1;
    vector e2;
    vector n;

    for (label i = index1+1; i < samplePoints.size(); i++)
    {
        e2 = samplePoints[i] - p0;

        scalar magE2 = mag(e2);

        if (magE2 > SMALL)
        {
            e2 /= magE2;

            n = e1^e2;

            scalar magN = mag(n);

            if (magN > SMALL)
            {
                index2 = i;
                n /= magN;
                break;
            }
        }
    }

Now my questions are:

• the condition for a "pass through" seems to be
  magE1 > SMALL and magN > SMALL ?
  Now I haven't found any definition of what SMALL may be?
  What is it? Where is it defined?
• What kind of operation is e1 /= magE1 ?
• What is the break command doing?
• What is n = e1^e2 doing? This is not a power-operation, right?!