BeginEdit method of DataGrid class, helps you to make each cell in customized edit mode. Ref at:
http://msdn.microsoft.com/en-us/library/cc189733.aspx[
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Herez the sample code in Load handler:
dgPointSpeedVector.CurrentCell = new DataGridCellInfo(
dgPointSpeedVector.Items[0], dgPointSpeedVector.Columns[3]);
dgPointSpeedVector.BeginEdit();