private static SymbolType QuerySymbolicExpression(SymbolicExpression symbolicExpression)
{
if (symbolicExpression.IsDataFrame())
{
return(SymbolType.DataFrame);
}
if (symbolicExpression.IsFunction())
{
return(SymbolType.Function);
}
if (symbolicExpression.IsMatrix())
{
return(SymbolType.Matrix);
}
if (symbolicExpression.IsList())
{
return(SymbolType.List);
}
if (symbolicExpression.IsVector())
{
return(SymbolType.Vector);
}
return(SymbolType.NonRVisType);
}
public static void RunRScript(SqlString script)
{
lock (_lock)
{
// initialize R engine
if (_engine == null)
{
SqlContext.Pipe.Send("Starting R engine");
REngine.SetEnvironmentVariables();
_console = new SqlConsole();
_engine = REngine.GetInstance(null, true, null, _console);
SqlContext.Pipe.Send("R engine has been started");
}
// Execute R script
SqlContext.Pipe.Send("Starting R script execution");
SymbolicExpression res = _engine.Evaluate(script.ToString());
// Parse and return results if any
if (res != null && res.IsDataFrame())
{
DataFrame df = res.AsDataFrame();
SqlMetaData[] cols = new SqlMetaData[df.ColumnCount];
for (int i = 0; i < df.ColumnCount; i++)
{
cols[i] = new SqlMetaData(df.ColumnNames[i], SqlDbType.Variant);
}
SqlDataRecord rec = new SqlDataRecord(cols);
SqlContext.Pipe.SendResultsStart(rec);
var rows = df.GetRows();
foreach (DataFrameRow row in rows)
{
for (int i = 0; i < df.ColumnCount; i++)
{
rec.SetValue(i, row[i]);
}
SqlContext.Pipe.SendResultsRow(rec);
}
SqlContext.Pipe.SendResultsEnd();
}
SqlContext.Pipe.Send("R script execution completed");
}
}