Method update

3rdparty/qwt/src/qwt_matrix_raster_data.cpp:400–417

}

void QwtMatrixRasterData::update()
{
    m_data->numRows = 0;
    m_data->dx = 0.0;
    m_data->dy = 0.0;

    if ( m_data->numColumns > 0 )
    {
        m_data->numRows = m_data->values.size() / m_data->numColumns;

        const QwtInterval xInterval = interval( Qt::XAxis );
        const QwtInterval yInterval = interval( Qt::YAxis );
        if ( xInterval.isValid() )
            m_data->dx = xInterval.width() / m_data->numColumns;
        if ( yInterval.isValid() )
            m_data->dy = yInterval.width() / m_data->numRows;
    }
}