Files
spark/src/DataStreamSuite/DataStream/Primitives/InterRow/RowDiffStream.cs
T
2024-02-08 14:11:10 -05:00

79 lines
2.9 KiB
C#

using BCG;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using ZstdSharp.Unsafe;
namespace bts {
public class RowDiffStream : ViewStream {
private ViewStream _vs;
private readonly string _order_col, _col_1, _col_2;
private readonly int _diff;
private IBlueTableSchema _out_schema;
private readonly string _diff_col_name;
public RowDiffStream(ViewStream vs, string order_col, string col_1, string col_2, int diff, string diff_col_name) {
_vs = vs;
_order_col = order_col;
_col_1 = col_1;
_col_2 = col_2;
_diff = diff;
_diff_col_name = diff_col_name;
}
private string _diff_col_name_perc {
get {
return $"{_diff_col_name}_percentage";
}
}
protected override void myOnFirstSubscriber() {
_vs.onChange += _handle_vs;
}
protected override void myOnLastSubscriber() {
_vs.onChange -= _handle_vs;
}
private void _handle_vs(object dp_obj) {
var dp = dp_obj as DataPacket;
IBlueRowCollection nrows = dp.newRows;
_out_schema = BlueDataUtility.add_column(nrows.schema, _diff_col_name, typeof(double));
_out_schema = BlueDataUtility.add_column(_out_schema, _diff_col_name_perc, typeof(double));
List<IBlueRow> row_list = new List<IBlueRow>();
foreach (IBlueRow r in nrows)
row_list.Add(r);
//OrderBy sorts in ascedning order
var sorted_rows = row_list.OrderBy(r => r[_order_col]).ToList();
var sorted_row_array = sorted_rows.ToArray();
// reverse it to make it descending
sorted_rows.Reverse();
//sort rows so we can do the diff
OrderedBlueTable rv = new OrderedBlueTable(_out_schema);
int i = 0;
foreach (IBlueRow r in sorted_rows) {
MutableBlueRow nr = new MutableBlueRow(_out_schema, r);
//So, in the expression "x - y," where y is subtracted from x, x is the minuend, and y is the subtrahend.
// we assume x - y, and name variables like that
double x = r.get<double>(_col_1);
int y_row_idx = i + _diff;
double diff = System.Double.NaN;
double perc = System.Double.NaN;
if (y_row_idx < sorted_rows.Count()) {
var y = sorted_rows[y_row_idx].get<double>(_col_2);
diff = x - y;
perc = 100.0 * diff / y;
}
nr.setValue(_diff_col_name, diff);
nr.setValue(_diff_col_name_perc, perc);
rv.addRow(nr);
i++;
}
var dp_out = BlueDataUtility.build_dp_inc(new_rows: rv, myLastValue as DataPacket, true);
myFireEvent(dp_out);
}
}
}