R/ml_feature_dct.R
ft_dct.RdA feature transformer that takes the 1D discrete cosine transform of a real vector. No zero padding is performed on the input vector. It returns a real vector of the same length representing the DCT. The return vector is scaled such that the transform matrix is unitary (aka scaled DCT-II).
ft_dct(
x,
input_col = NULL,
output_col = NULL,
inverse = FALSE,
uid = random_string("dct_"),
...
)
ft_discrete_cosine_transform(
x,
input_col,
output_col,
inverse = FALSE,
uid = random_string("dct_"),
...
)A spark_connection, ml_pipeline, or a tbl_spark.
The name of the input column.
The name of the output column.
Indicates whether to perform the inverse DCT (TRUE) or forward DCT (FALSE).
A character string used to uniquely identify the feature transformer.
Optional arguments; currently unused.
The object returned depends on the class of x. If it is a
spark_connection, the function returns a ml_estimator or a
ml_estimator object. If it is a ml_pipeline, it will return
a pipeline with the transformer or estimator appended to it. If a
tbl_spark, it will return a tbl_spark with the transformation
applied to it.
ft_discrete_cosine_transform() is an alias for ft_dct for backwards compatibility.
Other feature transformers:
ft_binarizer(),
ft_bucketizer(),
ft_chisq_selector(),
ft_count_vectorizer(),
ft_elementwise_product(),
ft_feature_hasher(),
ft_hashing_tf(),
ft_idf(),
ft_imputer(),
ft_index_to_string(),
ft_interaction(),
ft_lsh,
ft_max_abs_scaler(),
ft_min_max_scaler(),
ft_ngram(),
ft_normalizer(),
ft_one_hot_encoder(),
ft_one_hot_encoder_estimator(),
ft_pca(),
ft_polynomial_expansion(),
ft_quantile_discretizer(),
ft_r_formula(),
ft_regex_tokenizer(),
ft_robust_scaler(),
ft_sql_transformer(),
ft_standard_scaler(),
ft_stop_words_remover(),
ft_string_indexer(),
ft_tokenizer(),
ft_vector_assembler(),
ft_vector_indexer(),
ft_vector_slicer(),
ft_word2vec()