/// <summary>
/// Returns the <see cref="SchemaShape"/> of the schema which will be produced by the transformer.
/// Used for schema propagation and verification in a pipeline.
/// </summary>
public override SchemaShape GetOutputSchema(SchemaShape inputSchema)
{
Host.CheckValue(inputSchema, nameof(inputSchema));
var fakeSchema = FakeSchemaFactory.Create(inputSchema);
return(SchemaShape.Create(Transformer.GetOutputSchema(fakeSchema)));
}
public SchemaShape GetOutputSchema(SchemaShape inputSchema)
{
Host.CheckValue(inputSchema, nameof(inputSchema));
var fakeSchema = FakeSchemaFactory.Create(inputSchema);
var transformer = Fit(new EmptyDataView(Host, fakeSchema));
return(SchemaShape.Create(transformer.GetOutputSchema(fakeSchema)));
}
void SimpleTest()
{
var metadataBuilder = new DataViewSchema.Annotations.Builder();
metadataBuilder.Add("M", NumberDataViewType.Single, (ref float v) => v = 484f);
var schemaBuilder = new DataViewSchema.Builder();
schemaBuilder.AddColumn("A", new VectorDataViewType(NumberDataViewType.Single, 94));
schemaBuilder.AddColumn("B", new KeyDataViewType(typeof(uint), 17));
schemaBuilder.AddColumn("C", NumberDataViewType.Int32, metadataBuilder.ToAnnotations());
var shape = SchemaShape.Create(schemaBuilder.ToSchema());
var fakeSchema = FakeSchemaFactory.Create(shape);
var columnA = fakeSchema[0];
var columnB = fakeSchema[1];
var columnC = fakeSchema[2];
Assert.Equal("A", columnA.Name);
Assert.Equal(NumberDataViewType.Single, columnA.Type.GetItemType());
Assert.Equal(10, columnA.Type.GetValueCount());
Assert.Equal("B", columnB.Name);
Assert.Equal(InternalDataKind.U4, columnB.Type.GetRawKind());
Assert.Equal(10u, columnB.Type.GetKeyCount());
Assert.Equal("C", columnC.Name);
Assert.Equal(NumberDataViewType.Int32, columnC.Type);
var metaC = columnC.Annotations;
Assert.Single(metaC.Schema);
float mValue = -1;
metaC.GetValue("M", ref mValue);
Assert.Equal(default, mValue);
void SimpleTest()
{
var metadataBuilder = new MetadataBuilder();
metadataBuilder.Add("M", NumberType.R4, (ref float v) => v = 484f);
var schemaBuilder = new SchemaBuilder();
schemaBuilder.AddColumn("A", new VectorType(NumberType.R4, 94));
schemaBuilder.AddColumn("B", new KeyType(typeof(uint), 17));
schemaBuilder.AddColumn("C", NumberType.I4, metadataBuilder.GetMetadata());
var shape = SchemaShape.Create(schemaBuilder.GetSchema());
var fakeSchema = FakeSchemaFactory.Create(shape);
var columnA = fakeSchema[0];
var columnB = fakeSchema[1];
var columnC = fakeSchema[2];
Assert.Equal("A", columnA.Name);
Assert.Equal(NumberType.R4, columnA.Type.GetItemType());
Assert.Equal(10, columnA.Type.GetValueCount());
Assert.Equal("B", columnB.Name);
Assert.Equal(DataKind.U4, columnB.Type.GetRawKind());
Assert.Equal(10u, columnB.Type.GetKeyCount());
Assert.Equal("C", columnC.Name);
Assert.Equal(NumberType.I4, columnC.Type);
var metaC = columnC.Metadata;
Assert.Single(metaC.Schema);
float mValue = -1;
metaC.GetValue("M", ref mValue);
Assert.Equal(default, mValue);