ph-math/src/main/java/com/helger/numbercruncher/mathutils/InterpolationPolynomial.java
public float at (final float x)
  {
    if (m_nDataPoints < 2)
      return Float.NaN;

    float y = m_aDivDiff[0][0];
    float xFactor = 1;

    // Compute the value of the function.
    for (int order = 1; order < m_nDataPoints; ++order)
    {
      xFactor = xFactor * (x - m_aData[order - 1].getX ());
      y = y + xFactor * m_aDivDiff[0][order];
    }

    return y;
  }
public float at (final float x)
  {
    if (m_nDataPoints < 2)
      return Float.NaN;

    float y = m_aDivDiff[0][0];
    float xFactor = 1;

    // Compute the value of the function.
    for (int order = 1; order < m_nDataPoints; ++order)
    {
      xFactor = xFactor * (x - m_aData[order - 1].getX ());
      y = y + xFactor * m_aDivDiff[0][order];
    }

    return y;
  }
Return the value of the polynomial interpolation function at x.
(Implementation of Evaluatable.)

@param x
the value of x
@return the value of the function at x