public void DataViewGroupByClause()
{
DataView original = GetTestFrame();//.WhereNotNull("male");
DataFrame grouped = original.GroupBy("male", v => v.Column <double>("height").Mean(), "meanHeight");
foreach (DataRow row in grouped.Rows)
{
object value = row["male"];
// r["male"] == value doesn't work, because this is an object comparison,
// and two equal values boxed to objects are not equal. This is a problem.
DataView selected = original.Where <bool?>("male", m => m.Equals(value));
//DataView selected = original.Where(r => (r["male"] == value));
double height = selected.Column <double>("height").Mean();
Assert.IsTrue((double)row["meanHeight"] == height);
}
}
public void DataViewOrderByColumnFunc()
{
DataView original = GetTestFrame();
// This should support nulls
DataView reordered = original.OrderBy("name");
//DataView reordered = original.OrderBy<string>("name", String.Compare);
Assert.IsTrue(reordered.Columns.Count == original.Columns.Count);
Assert.IsTrue(reordered.Rows.Count == original.Rows.Count);
List <string> reorderedCopy = original.Column <string>("name").ToList();
reorderedCopy.Sort();
DataColumn <string> reorderedColumn = reordered.Column <string>("name");
for (int i = 0; i < reorderedColumn.Count; i++)
{
Assert.IsTrue(reorderedColumn[i] == reorderedCopy[i]);
}
}