ph-math/src/main/java/com/helger/numbercruncher/matrix/SquareMatrix.java
private void _set (final Matrix m)
  {
    this.m_nRows = this.m_nCols = Math.min (m.m_nRows, m.m_nCols);
    this.m_aValues = m.m_aValues;
  }
private void _set (final Matrix m)
  {
    this.m_nRows = this.m_nCols = Math.min (m.m_nRows, m.m_nCols);
    this.m_aValues = m.m_aValues;
  }
Set this square matrix from another matrix. Note that this matrix will
reference the values of the argument matrix. If the values are not square,
only the upper left square is used.

@param m
the 2-d array of values