protected override Delegate[] GetGetters(DataViewRow output, Func<int, bool> predicate)
{
Host.Assert(Bindings.DerivedColumnCount == 1);
Host.AssertValue(output);
Host.AssertValue(predicate);
Host.Assert(output.Schema == Bindings.RowMapper.OutputSchema);
Host.Assert(Bindings.InfoCount == output.Schema.Count + 1);
var getters = new Delegate[Bindings.InfoCount];
// Deal with the predicted label column.
int delta = Bindings.DerivedColumnCount;
Delegate delScore = null;
if (predicate(0))
{
Host.Assert(output.IsColumnActive(output.Schema[Bindings.ScoreColumnIndex]));
getters[0] = GetPredictedLabelGetter(output, out delScore);
}
for (int iinfo = delta; iinfo < getters.Length; iinfo++)
{
if (!predicate(iinfo))
continue;
if (iinfo == delta + Bindings.ScoreColumnIndex && delScore != null)
getters[iinfo] = delScore;
else
getters[iinfo] = GetGetterFromRow(output, iinfo - delta);
}
return getters;
}
/// <summary>
/// Given a row, returns a one-row data view. This is useful for cases where you have a row, and you
/// wish to use some facility normally only exposed to dataviews. (For example, you have an <see cref="DataViewRow"/>
/// but want to save it somewhere using a <see cref="Microsoft.ML.Data.IO.BinarySaver"/>.)
/// Note that it is not possible for this method to ensure that the input <paramref name="row"/> does not
/// change, so users of this convenience must take care of what they do with the input row or the data
/// source it came from, while the returned dataview is potentially being used.
/// </summary>
/// <param name="env">An environment used to create the host for the resulting data view</param>
/// <param name="row">A row, whose columns must all be active</param>
/// <returns>A single-row data view incorporating that row</returns>
public static IDataView RowAsDataView(IHostEnvironment env, DataViewRow row)
{
Contracts.CheckValue(env, nameof(env));
env.CheckValue(row, nameof(row));
env.CheckParam(Enumerable.Range(0, row.Schema.Count).All(c => row.IsColumnActive(c)), nameof(row), "Some columns were inactive");
return(new OneRowDataView(env, row));
}
protected static ValueGetter <T> GetGetterFromRow <T>(DataViewRow output, int col)
{
Contracts.AssertValue(output);
Contracts.Assert(0 <= col && col < output.Schema.Count);
Contracts.Assert(output.IsColumnActive(output.Schema[col]));
return(output.GetGetter <T>(output.Schema[col]));
}
internal DataViewRow GetStatefulRows(DataViewRow input, IRowToRowMapper mapper, IEnumerable <DataViewSchema.Column> activeColumns, List <StatefulRow> rows)
{
Contracts.CheckValue(input, nameof(input));
Contracts.CheckValue(activeColumns, nameof(activeColumns));
IRowToRowMapper[] innerMappers = new IRowToRowMapper[0];
if (mapper is CompositeRowToRowMapper compositeMapper)
{
innerMappers = compositeMapper.InnerMappers;
}
var activeIndices = new HashSet <int>(activeColumns.Select(c => c.Index));
if (innerMappers.Length == 0)
{
bool differentActive = false;
for (int c = 0; c < input.Schema.Count; ++c)
{
bool wantsActive = activeIndices.Contains(c);
bool isActive = input.IsColumnActive(input.Schema[c]);
differentActive |= wantsActive != isActive;
if (wantsActive && !isActive)
{
throw Contracts.ExceptParam(nameof(input), $"Mapper required column '{input.Schema[c].Name}' active but it was not.");
}
}
var row = mapper.GetRow(input, activeColumns);
if (row is StatefulRow statefulRow)
{
rows.Add(statefulRow);
}
return(row);
}
// For each of the inner mappers, we will be calling their GetRow method, but to do so we need to know
// what we need from them. The last one will just have the input, but the rest will need to be
// computed based on the dependencies of the next one in the chain.
var deps = new IEnumerable <DataViewSchema.Column> [innerMappers.Length];
deps[deps.Length - 1] = activeColumns;
for (int i = deps.Length - 1; i >= 1; --i)
{
deps[i - 1] = innerMappers[i].GetDependencies(deps[i]);
}
DataViewRow result = input;
for (int i = 0; i < innerMappers.Length; ++i)
{
result = GetStatefulRows(result, innerMappers[i], deps[i], rows);
if (result is StatefulRow statefulResult)
{
rows.Add(statefulResult);
}
}
return(result);
}
internal DataViewRow GetStatefulRows(DataViewRow input, IRowToRowMapper mapper, Func <int, bool> active, List <StatefulRow> rows)
{
Contracts.CheckValue(input, nameof(input));
Contracts.CheckValue(active, nameof(active));
IRowToRowMapper[] innerMappers = new IRowToRowMapper[0];
if (mapper is CompositeRowToRowMapper compositeMapper)
{
innerMappers = compositeMapper.InnerMappers;
}
if (innerMappers.Length == 0)
{
bool differentActive = false;
for (int c = 0; c < input.Schema.Count; ++c)
{
bool wantsActive = active(c);
bool isActive = input.IsColumnActive(c);
differentActive |= wantsActive != isActive;
if (wantsActive && !isActive)
{
throw Contracts.ExceptParam(nameof(input), $"Mapper required column '{input.Schema[c].Name}' active but it was not.");
}
}
var row = mapper.GetRow(input, active);
if (row is StatefulRow statefulRow)
{
rows.Add(statefulRow);
}
return(row);
}
// For each of the inner mappers, we will be calling their GetRow method, but to do so we need to know
// what we need from them. The last one will just have the input, but the rest will need to be
// computed based on the dependencies of the next one in the chain.
var deps = new Func <int, bool> [innerMappers.Length];
deps[deps.Length - 1] = active;
for (int i = deps.Length - 1; i >= 1; --i)
{
var inputCols = innerMappers[i].OutputSchema.Where(c => deps[i](c.Index));
var cols = innerMappers[i].GetDependencies(inputCols).ToArray();
deps[i - 1] = c => cols.Length > 0 ? cols.Any(col => col.Index == c) : false;
}
DataViewRow result = input;
for (int i = 0; i < innerMappers.Length; ++i)
{
result = GetStatefulRows(result, innerMappers[i], deps[i], rows);
if (result is StatefulRow statefulResult)
{
rows.Add(statefulResult);
}
}
return(result);
}
/// <summary>
/// Returns an appropriate <see cref="ValueGetter{T}"/> for a row given an active column
/// index, but as a delegate. The type parameter for the delegate will correspond to the
/// raw type of the column.
/// </summary>
/// <param name="row">The row to get the getter for</param>
/// <param name="col">The column index, which must be active on that row</param>
/// <returns>The getter as a delegate</returns>
public static Delegate GetGetterAsDelegate(DataViewRow row, int col)
{
Contracts.CheckValue(row, nameof(row));
Contracts.CheckParam(0 <= col && col < row.Schema.Count, nameof(col));
Contracts.CheckParam(row.IsColumnActive(row.Schema[col]), nameof(col), "column was not active");
return(Utils.MarshalInvoke(_getGetterAsDelegateCoreMethodInfo, row.Schema[col].Type.RawType, row, col));
}
protected ValueGetter <T> GetSrcGetter <T>(DataViewRow input, int iinfo)
{
Host.AssertValue(input);
Host.Assert(0 <= iinfo && iinfo < Infos.Length);
int src = Infos[iinfo].Source;
Host.Assert(input.IsColumnActive(input.Schema[src]));
return(input.GetGetter <T>(input.Schema[src]));
}
public bool CanShuffle => true; // The shuffling is even uniformly IID!! :)
public OneRowDataView(IHostEnvironment env, DataViewRow row)
{
Contracts.AssertValue(env);
_host = env.Register("OneRowDataView");
_host.AssertValue(row);
_host.Assert(Enumerable.Range(0, row.Schema.Count).All(c => row.IsColumnActive(c)));
_row = row;
}
private ValueGetter <T> GetSrcGetter <T>(DataViewRow input, int iinfo)
{
Host.AssertValue(input);
Host.Assert(0 <= iinfo && iinfo < _parent.ColumnPairs.Length);
var srcCol = input.Schema[_cols[iinfo]];
Host.Assert(input.IsColumnActive(srcCol));
return(input.GetGetter <T>(srcCol));
}
protected static Delegate GetGetterFromRow(DataViewRow row, int col)
{
Contracts.AssertValue(row);
Contracts.Assert(0 <= col && col < row.Schema.Count);
Contracts.Assert(row.IsColumnActive(row.Schema[col]));
var type = row.Schema[col].Type;
return(Utils.MarshalInvoke(_getGetterFromRowMethodInfo, type.RawType, row, col));
}
/// <summary>
/// Given an IRow, and column index, return a function that utilizes the
/// <see cref="Conversions.GetStringConversion{TSrc}(DataViewType)"/> on the input
/// rows to map the values in the column, whatever type they may be, into a string
/// builder. This method will obviously succeed only if there is a string conversion
/// into the required type. This method can be useful if you want to output a value
/// as a string in a generic way, but don't really care how you do it.
/// </summary>
public static ValueGetter <StringBuilder> GetGetterAsStringBuilder(DataViewRow row, int col)
{
Contracts.CheckValue(row, nameof(row));
Contracts.CheckParam(0 <= col && col < row.Schema.Count, nameof(col));
Contracts.CheckParam(row.IsColumnActive(col), nameof(col), "column was not active");
var typeSrc = row.Schema[col].Type;
Contracts.Check(typeSrc is PrimitiveDataViewType, "Source column type must be primitive");
return(Utils.MarshalInvoke(GetGetterAsStringBuilderCore <int>, typeSrc.RawType, typeSrc, row, col));
}
/// <summary>
/// Returns whether the given column is active in this row.
/// </summary>
public override bool IsColumnActive(DataViewSchema.Column column)
{
bool isSrc;
int index = _parent._bindings.MapColumnIndex(out isSrc, column.Index);
if (isSrc)
{
return(_input.IsColumnActive(_input.Schema[index]));
}
return(_getters[index] != null);
}
public override bool IsColumnActive(int col)
{
bool isSrc;
int index = _parent._bindings.MapColumnIndex(out isSrc, col);
if (isSrc)
{
return(_input.IsColumnActive((index)));
}
return(_getters[index] != null);
}
/// <summary>
/// Returns whether the given column is active in this row.
/// </summary>
public override bool IsColumnActive(DataViewSchema.Column column)
{
Contracts.CheckParam(column.Index < Schema.Count, nameof(column));
bool isSrc;
int iCol = _parent._bindings.MapColumnIndex(out isSrc, column.Index);
if (isSrc)
{
return(_input.IsColumnActive(_input.Schema[iCol]));
}
return(_appendedRow.IsColumnActive(_appendedRow.Schema[iCol]));
}
protected static Delegate GetGetterFromRow(DataViewRow row, int col)
{
Contracts.AssertValue(row);
Contracts.Assert(0 <= col && col < row.Schema.Count);
Contracts.Assert(row.IsColumnActive(col));
var type = row.Schema[col].Type;
Func <DataViewRow, int, ValueGetter <int> > del = GetGetterFromRow <int>;
var meth = del.GetMethodInfo().GetGenericMethodDefinition().MakeGenericMethod(type.RawType);
return((Delegate)meth.Invoke(null, new object[] { row, col }));
}
public override bool IsColumnActive(int col)
{
Contracts.CheckParam(0 <= col && col < Schema.Count, nameof(col));
bool isSrc;
int iCol = _parent._bindings.MapColumnIndex(out isSrc, col);
if (isSrc)
{
return(_input.IsColumnActive(iCol));
}
return(_appendedRow.IsColumnActive(iCol));
}
/// <summary>
/// Given the item type, typeDst, a row, and column index, return a ValueGetter for the vector-valued
/// column with a conversion to a vector of typeDst, if needed. This is the weakly typed version of
/// <see cref="GetVecGetterAs{TDst}(PrimitiveDataViewType, DataViewRow, int)"/>.
/// </summary>
public static Delegate GetVecGetterAs(PrimitiveDataViewType typeDst, DataViewRow row, int col)
{
Contracts.CheckValue(typeDst, nameof(typeDst));
Contracts.CheckValue(row, nameof(row));
Contracts.CheckParam(0 <= col && col < row.Schema.Count, nameof(col));
Contracts.CheckParam(row.IsColumnActive(col), nameof(col), "column was not active");
var typeSrc = row.Schema[col].Type as VectorType;
Contracts.Check(typeSrc != null, "Source column type must be vector");
Func <VectorType, PrimitiveDataViewType, GetterFactory, ValueGetter <VBuffer <int> > > del = GetVecGetterAsCore <int, int>;
var methodInfo = del.GetMethodInfo().GetGenericMethodDefinition().MakeGenericMethod(typeSrc.ItemType.RawType, typeDst.RawType);
return((Delegate)methodInfo.Invoke(null, new object[] { typeSrc, typeDst, GetterFactory.Create(row, col) }));
}
/// <summary>
/// Given a destination type, IRow, and column index, return a ValueGetter for the column
/// with a conversion to typeDst, if needed. This is a weakly typed version of
/// <see cref="GetGetterAs{TDst}"/>.
/// </summary>
/// <seealso cref="GetGetterAs{TDst}"/>
public static Delegate GetGetterAs(DataViewType typeDst, DataViewRow row, int col)
{
Contracts.CheckValue(typeDst, nameof(typeDst));
Contracts.CheckParam(typeDst is PrimitiveDataViewType, nameof(typeDst));
Contracts.CheckValue(row, nameof(row));
Contracts.CheckParam(0 <= col && col < row.Schema.Count, nameof(col));
Contracts.CheckParam(row.IsColumnActive(row.Schema[col]), nameof(col), "column was not active");
var typeSrc = row.Schema[col].Type;
Contracts.Check(typeSrc is PrimitiveDataViewType, "Source column type must be primitive");
Func <DataViewType, DataViewType, DataViewRow, int, ValueGetter <int> > del = GetGetterAsCore <int, int>;
var methodInfo = del.GetMethodInfo().GetGenericMethodDefinition().MakeGenericMethod(typeSrc.RawType, typeDst.RawType);
return((Delegate)methodInfo.Invoke(null, new object[] { typeSrc, typeDst, row, col }));
}
public DataViewRow GetRow(DataViewRow input, Func <int, bool> active)
{
Contracts.CheckValue(input, nameof(input));
Contracts.CheckValue(active, nameof(active));
Contracts.CheckParam(input.Schema == InputSchema, nameof(input), "Schema did not match original schema");
if (InnerMappers.Length == 0)
{
bool differentActive = false;
for (int c = 0; c < input.Schema.Count; ++c)
{
bool wantsActive = active(c);
bool isActive = input.IsColumnActive(c);
differentActive |= wantsActive != isActive;
if (wantsActive && !isActive)
{
throw Contracts.ExceptParam(nameof(input), $"Mapper required column '{input.Schema[c].Name}' active but it was not.");
}
}
return(input);
}
// For each of the inner mappers, we will be calling their GetRow method, but to do so we need to know
// what we need from them. The last one will just have the input, but the rest will need to be
// computed based on the dependencies of the next one in the chain.
var deps = new Func <int, bool> [InnerMappers.Length];
deps[deps.Length - 1] = active;
for (int i = deps.Length - 1; i >= 1; --i)
{
var outputColumns = InnerMappers[i].OutputSchema.Where(c => deps[i](c.Index));
var cols = InnerMappers[i].GetDependencies(outputColumns).ToArray();
deps[i - 1] = c => cols.Length > 0 ? cols.Any(col => col.Index == c) : false;
}
DataViewRow result = input;
for (int i = 0; i < InnerMappers.Length; ++i)
{
result = InnerMappers[i].GetRow(result, deps[i]);
}
return(result);
}
protected override Delegate MakeGetter(DataViewRow input, int iinfo, Func <int, bool> activeOutput, out Action disposer)
{
Host.AssertValue(input);
disposer = null;
Host.Assert(input.IsColumnActive(_scoreColIndex));
var getScore = input.GetGetter <float>(_scoreColIndex);
float score = default;
ValueGetter <float> probability = (ref float dst) =>
{
getScore(ref score);
dst = _calibrator.PredictProbability(score);
};
return(probability);
}
DataViewRow IRowToRowMapper.GetRow(DataViewRow input, IEnumerable <DataViewSchema.Column> activeColumns)
{
Contracts.CheckValue(input, nameof(input));
Contracts.CheckValue(activeColumns, nameof(activeColumns));
Contracts.CheckParam(input.Schema == InputSchema, nameof(input), "Schema did not match original schema");
var activeIndices = activeColumns.Select(c => c.Index).ToArray();
if (InnerMappers.Length == 0)
{
bool differentActive = false;
for (int c = 0; c < input.Schema.Count; ++c)
{
bool wantsActive = activeIndices.Contains(c);
bool isActive = input.IsColumnActive(input.Schema[c]);
differentActive |= wantsActive != isActive;
if (wantsActive && !isActive)
{
throw Contracts.ExceptParam(nameof(input), $"Mapper required column '{input.Schema[c].Name}' active but it was not.");
}
}
return(input);
}
// For each of the inner mappers, we will be calling their GetRow method, but to do so we need to know
// what we need from them. The last one will just have the input, but the rest will need to be
// computed based on the dependencies of the next one in the chain.
IEnumerable <DataViewSchema.Column>[] deps = new IEnumerable <DataViewSchema.Column> [InnerMappers.Length];
deps[deps.Length - 1] = OutputSchema.Where(c => activeIndices.Contains(c.Index));
for (int i = deps.Length - 1; i >= 1; --i)
{
deps[i - 1] = InnerMappers[i].GetDependencies(deps[i]);
}
DataViewRow result = input;
for (int i = 0; i < InnerMappers.Length; ++i)
{
result = InnerMappers[i].GetRow(result, deps[i]);
}
return(result);
}
protected override Delegate GetPredictedLabelGetter(DataViewRow output, out Delegate scoreGetter)
{
Host.AssertValue(output);
Host.Assert(output.Schema == Bindings.RowMapper.OutputSchema);
Host.Assert(output.IsColumnActive(output.Schema[Bindings.ScoreColumnIndex]));
var scoreColumn = output.Schema[Bindings.ScoreColumnIndex];
ValueGetter <float> mapperScoreGetter = output.GetGetter <float>(scoreColumn);
long cachedPosition = -1;
float score = 0;
ValueGetter <float> scoreFn =
(ref float dst) =>
{
EnsureCachedPosition(ref cachedPosition, ref score, output, mapperScoreGetter);
dst = score;
};
scoreGetter = scoreFn;
if (Bindings.PredColType is KeyDataViewType)
{
ValueGetter <uint> predFnAsKey =
(ref uint dst) =>
{
EnsureCachedPosition(ref cachedPosition, ref score, output, mapperScoreGetter);
GetPredictedLabelCoreAsKey(score, ref dst);
};
return(predFnAsKey);
}
ValueGetter <bool> predFn =
(ref bool dst) =>
{
EnsureCachedPosition(ref cachedPosition, ref score, output, mapperScoreGetter);
GetPredictedLabelCore(score, ref dst);
};
return(predFn);
}
protected override Delegate GetPredictedLabelGetter(DataViewRow output, out Delegate scoreGetter)
{
Contracts.AssertValue(output);
Contracts.Assert(output.Schema == Bindings.RowMapper.OutputSchema);
Contracts.Assert(output.IsColumnActive(output.Schema[Bindings.ScoreColumnIndex]));
ValueGetter <VBuffer <float> > mapperScoreGetter = output.GetGetter <VBuffer <float> >(output.Schema[Bindings.ScoreColumnIndex]);
long cachedPosition = -1;
VBuffer <float> score = default(VBuffer <float>);
int keyCount = Bindings.PredColType is KeyType key?key.GetCountAsInt32(Host) : 0;
int scoreLength = keyCount;
ValueGetter <uint> predFn =
(ref uint dst) =>
{
EnsureCachedPosition(ref cachedPosition, ref score, output, mapperScoreGetter);
Contracts.Check(score.Length == scoreLength);
int index = VectorUtils.ArgMin(in score);
if (index < 0)
{
dst = 0;
}
else
{
dst = (uint)index + 1;
}
};
ValueGetter <VBuffer <float> > scoreFn =
(ref VBuffer <float> dst) =>
{
EnsureCachedPosition(ref cachedPosition, ref score, output, mapperScoreGetter);
Contracts.Check(score.Length == scoreLength);
score.CopyTo(ref dst);
};
scoreGetter = scoreFn;
return(predFn);
}
