Comments by Leslie Zhai (Top 2 by date)

Leslie Zhai 2-Aug-12 21:28pm View

Thank CPanllini, it might be MYSQL mysql static struct object, then mysql_init(&mysql), it is bad 'an earlier' link to static mysql struct object;

But in my situation, MYSQL* mysql = mysql_init(NULL); it my_malloc mysql pointer object, it is suitable to set the funtion pointer address.

Leslie Zhai 7-Apr-11 4:25am View

Deleted

DeTrend.cs library in C#


<pre lang="cs">
// TODO: DeTrend class acts like mathwords detrend(...)
public class DeTrend
{
    public DeTrend(int nWindowSize)
    {
        m_nWindowSize = nWindowSize;
        m_TrendList = new LinkedList<float>();
    }

    public void Dispose()
    {
        if (null != m_TrendList) m_TrendList.Clear(); m_TrendList = null;
    }

    public void Update(float[] inY, float[] outY, int nPointSize)
    {
        int i;
        m_nPointSize = nPointSize;
        if (m_nPointSize < m_nWindowSize) 
        {
            throw new Exception("nPointSize < nWindowSize");
        }
        for (i = 0; i < m_nPointSize; i++)
        {
            m_TrendList.AddLast(inY[i]);
        }
        if (m_bFirstCall)
        {
            m_CurIter = m_TrendList.First;
        }
        for (i = 0; i < m_nPointSize; i++)
        {
            // FIXME: m_CurIter became to null after the first call
            outY[i] = m_CurIter.Value - m_PreNMeanVal();
            m_CurIter = m_CurIter.Next;
        }
        i = m_nPointSize - m_nWindowSize;
        while (0 != i)
        {
            m_TrendList.RemoveFirst();
            i--;
        }
        m_bFirstCall = false;
    }

    #region Private Variable
    private bool m_bFirstCall = true;
    private int m_nWindowSize = 101;
    private int m_nPointSize = 200;
    private LinkedList<float> m_TrendList = null;
    private LinkedListNode<float> m_CurIter = null;
    #endregion

    // XXX: What is the Preview N Mean Value?
    private float m_PreNMeanVal()
    {
        float nRet = 0.0f;
        float nTotal = 0.0f;
        int i, nCount = 0;
        LinkedListNode<float> iter;
        for (iter = m_TrendList.First; m_CurIter != iter; ) iter = iter.Next;
        for (i = 0; i < m_nWindowSize && iter != m_TrendList.First; i++)
        {
            nTotal += iter.Value;
            nCount++;
            iter = iter.Previous;
        }
        if (0 == nCount) return nRet;
        nRet = nTotal / nCount;
        return nRet;
    }
}
</pre>

LibDeTrend.cpp can be DllImport by C#


<pre lang="cpp">
...
#include <list>

///////////////////////////////////////////////////////////////////////////////
// DeTrend Class
namespace CCTEC 
{
    class DeTrend 
    {
    // Construct / Destruct
    public:
        DeTrend(int nWindowSize) 
        {
            m_nWindowSize = nWindowSize;
            m_bFirstCall = true; 
        }
        ~DeTrend() { m_TrendList.clear(); }

    // Operation
    public:
        void Update(float *inY, float *outY, int nPointSize) 
        {
            int i;
            m_nPointSize = nPointSize;
            if (m_nPointSize < m_nWindowSize) throw "WindowSize > PointSize";
            for (i = 0; i < m_nPointSize; i++) 
            {
                m_TrendList.push_back(inY[i]);
            }
            if (m_bFirstCall) 
            {
                m_CurIter = m_TrendList.begin();
            }
            for (i = 0; i < m_nPointSize; i++, m_CurIter++) 
            {
                outY[i] = *m_CurIter - m_PreNMeanVal();
            }
            i = m_nPointSize - m_nWindowSize;
            while (i) 
            {
                m_TrendList.pop_front();
                i--;
            }
            m_bFirstCall = false;
        }

    // Attribute
    private:
        int m_nWindowSize;
        int m_nPointSize;
        bool m_bFirstCall;
        std::list<float> m_TrendList;
        std::list<float>::iterator m_CurIter;

    // Operation
    private:
        float m_PreNMeanVal() 
        {
            float nRet = 0.0f;
            float nTotal = 0.0f;
            int i, nCount = 0;
            std::list<float>::iterator iter;
            for (iter = m_TrendList.begin(); m_CurIter != iter;) iter++;
            for (i = 0; i < m_nWindowSize && iter != m_TrendList.begin(); i++, iter--)