private DataViewRowCursor GetRowCursor(IEnumerable <DataViewSchema.Column> columnsNeeded, Random rand,
DelegateGetRowCursor getterCursor)
{
int index = SchemaHelper.GetColumnIndex(Source.Schema, _parent.InputName);
if (columnsNeeded.Where(c => c.Index == index).Any())
{
var newCols = SchemaHelper.ColumnsNeeded(columnsNeeded, Schema, index, Schema.Count);
var oldCols = SchemaHelper.ColumnsNeeded(newCols, Source.Schema);
var cursor = getterCursor(oldCols, rand);
return(new MemoryCursor <TSrc, TDst>(this, cursor, index));
}
else
{
// The new column is not required. We do not need to compute it. But we need to keep the same schema.
return(new SameCursor(getterCursor(columnsNeeded, rand), Schema));
}
}
private DataViewRowCursor GetRowCursor(IEnumerable <DataViewSchema.Column> columnsNeeded, Random rand,
DelegateGetRowCursor getterCursor)
{
ComputeNearestNeighbors();
_host.AssertValue(_input, "_input");
var schema = _input.Schema;
if (columnsNeeded.Where(c => c.Index == _input.Schema.Count).Any())
{
var newColumns = PredicatePropagation(columnsNeeded);
var oldCols = SchemaHelper.ColumnsNeeded(newColumns, schema);
var featureIndex = SchemaHelper.GetColumnIndexDC(Schema, _args.column);
return(new NearestNeighborsCursor(getterCursor(oldCols, rand), this, newColumns, featureIndex));
}
else
{
// The new column is not required. We do not need to compute it. But we need to keep the same schema.
var oldCols = SchemaHelper.ColumnsNeeded(columnsNeeded, schema);
return(new SameCursor(getterCursor(oldCols, rand), Schema));
}
}
private DataViewRowCursor GetRowCursor(IEnumerable <DataViewSchema.Column> columnsNeeded, Random rand,
DelegateGetRowCursor getterCursor)
{
var kind = _toShake[0].OutputType.IsVector()
? _toShake[0].OutputType.ItemType().RawKind()
: _toShake[0].OutputType.RawKind();
var newCols = PredicatePropagation(columnsNeeded);
var oldCols = SchemaHelper.ColumnsNeeded(newCols, _input.Schema);
switch (kind)
{
case DataKind.Single:
var cursor = getterCursor(oldCols, rand);
return(new ShakeInputCursor <TInput, float>(this, cursor, newCols, _args, _inputCol, _toShake, _shakingValues,
(float x, float y) => { return x + y; }));
default:
throw _host.Except("Not supported RawKind {0}", _toShake[0].OutputType.RawKind());
}
}
private DataViewRowCursor GetRowCursor(IEnumerable <DataViewSchema.Column> columnsNeeded, Random rand,
DelegateGetRowCursor getterCursor)
{
int classColumn = -1;
if (!string.IsNullOrEmpty(_args.column))
{
classColumn = SchemaHelper.GetColumnIndex(_input.Schema, _args.column);
}
if (_args.cache)
{
LoadCache(rand);
}
else
{
Contracts.Assert(_cacheReplica == null);
}
var cursor = getterCursor(columnsNeeded, rand);
if (classColumn == -1)
{
return(new ResampleCursor <float>(this, cursor, columnsNeeded, _args.lambda,
_args.seed, rand, _cacheReplica, SchemaHelper._dc(classColumn, cursor),
float.NaN));
}
var newColumns = columnsNeeded.ToList();
newColumns.Add(Schema.Where(c => c.Index == classColumn).First());
var type = _input.Schema[classColumn].Type;
switch (type.RawKind())
{
case DataKind.Boolean:
bool clbool;
if (!bool.TryParse(_args.classValue, out clbool))
{
throw _host.Except("Unable to parse '{0}'.", _args.classValue);
}
return(new ResampleCursor <bool>(this, cursor, newColumns,
_args.lambda, _args.seed, rand, _cacheReplica,
SchemaHelper._dc(classColumn, cursor), clbool));
case DataKind.UInt32:
uint cluint;
if (!uint.TryParse(_args.classValue, out cluint))
{
throw _host.Except("Unable to parse '{0}'.", _args.classValue);
}
return(new ResampleCursor <uint>(this, cursor, newColumns,
_args.lambda, _args.seed, rand, _cacheReplica,
SchemaHelper._dc(classColumn, cursor), cluint));
case DataKind.Single:
float clfloat;
if (!float.TryParse(_args.classValue, out clfloat))
{
throw _host.Except("Unable to parse '{0}'.", _args.classValue);
}
return(new ResampleCursor <float>(this, cursor, newColumns,
_args.lambda, _args.seed, rand, _cacheReplica,
SchemaHelper._dc(classColumn, cursor), clfloat));
case DataKind.String:
var cltext = new ReadOnlyMemory <char>(_args.classValue.ToCharArray());
return(new ResampleCursor <ReadOnlyMemory <char> >(this, cursor, newColumns,
_args.lambda, _args.seed, rand, _cacheReplica,
SchemaHelper._dc(classColumn, cursor), cltext));
default:
throw _host.Except("Unsupported type '{0}'", type);
}
}
