/// <summary>
/// Changes the channel units
/// </summary>
/// <param name="UnitFrom">Unit name to change from. If no match, channel is not changing</param>
/// <param name="UnitTo">Unit name to change to</param>
/// <param name="gain">Conversion gain</param>
/// <param name="offset">Conversion offset</param>
public override bool ChangeUnits(string UnitFrom, string UnitTo, double gain, double offset)
{
if (this.Unit != UnitFrom)
{
return(false);
}
this.Unit = UnitTo;
string filename = m_Parent.LogDataName;
if (!File.Exists(filename))
{
return(false);
}
FileStream reader_writer = File.Open(filename, FileMode.Open, System.IO.FileAccess.ReadWrite, FileShare.Read);
long startPosition = m_Parent.DataStartPosition + (long)((this.LogColumnStart + 1) << 2);
reader_writer.Seek(startPosition, SeekOrigin.Begin);
byte[] buffer = new byte[LogDimension << 2];
long step = (long)(LogDimension << 2);
NumberUnion nu = new NumberUnion();
long totallength = (reader_writer.Length - m_Parent.DataStartPosition) / m_Parent.RecordWidth;
for (long k = 0; k < totallength; k++)
{
int i = reader_writer.Read(buffer, 0, buffer.Length);
if (i < buffer.Length)
{
break;
}
for (int j = 0; j < step; j += 4)
{
double d = Convert.ToDouble(BufferConverter.GetBytesFloat(buffer, nu, j));
if (d <= -1.0e30)
{
continue;
}
d = d * gain + offset;
BufferConverter.SetBytesFloat(buffer, nu, Convert.ToSingle(d), j);
}
reader_writer.Seek(-step, SeekOrigin.Current);
reader_writer.Write(buffer, 0, buffer.Length);
reader_writer.Seek(m_Parent.RecordWidth - step, SeekOrigin.Current);
}
reader_writer.Close();
if (!Double.IsNaN(this.Average))
{
this.Average = this.Average * gain + offset;
}
if (!Double.IsNaN(this.MinValue))
{
this.MinValue = this.MinValue * gain + offset;
}
if (!Double.IsNaN(this.MaxValue))
{
this.MaxValue = this.MaxValue * gain + offset;
}
return(true);
}
private void FloatBufferSaveProcessor(FileStream writer, int dimension)
{
long startPosition = m_Parent.DataStartPosition + (long)((this.LogColumnStart + dimension + 1) << 2);
writer.Seek(startPosition, SeekOrigin.Begin);
byte[] buffer = new byte[4];
NumberUnion nu = new NumberUnion();
for (int i = 0; i < Data.Count; i++)
{
double d = Data[i];
if (Double.IsNaN(d))
{
d = -1.0e30;
}
BufferConverter.SetBytesFloat(buffer, nu, Convert.ToSingle(d), 0);
writer.Write(buffer, 0, buffer.Length);
writer.Seek(m_Parent.RecordWidth - 4, SeekOrigin.Current);
}
}
