0
我對Apache Spark和MLib很陌生,試圖完成我的第一個多類分類模型。我停留在一些點...這裏是我的代碼:Spark中的多類分類與術語頻率
val input = sc.textFile("cars2.csv").map(line => line.split(";").toSeq)
創建數據幀:
val sql = new SQLContext(sc)
val schema = StructType(List(StructField("Description", StringType), StructField("Brand", StringType), StructField("Fuel", StringType)))
val dataframe = sql.createDataFrame(input.map(row => Row(row(0), row(1), row(2))), schema)
我的數據幀是這樣的:
+-----------------+----------+------+
| Description| Brand| Fuel|
+-----------------+----------+------+
| giulietta 1.4TB|alfa romeo|PETROL|
| 4c|alfa romeo|PETROL|
| giulietta 2.0JTD|alfa romeo|DIESEL|
| Mito 1.4 Tjet |alfa romeo|PETROL|
| a1 1.4 TFSI| AUDI|PETROL|
| a1 1.0 TFSI| AUDi|PETROL|
| a3 1.4 TFSI| AUDI|PETROL|
| a3 1.2 TFSI| AUDI|PETROL|
| a3 2.0 Tdi| AUDI|DIESEL|
| a3 1.6 TDi| AUDI|DIESEL|
| a3 1.8tsi| AUDI|PETROL|
| RS3 | AUDI|PETROL|
| S3| AUDI|PETROL|
| A4 2.0TDI| AUDI|DIESEL|
| A4 2.0TDI| AUDI|DIESEL|
| A4 1.4 tfsi| AUDI|PETROL|
| A4 2.0TFSI| AUDI|PETROL|
| A4 3.0TDI| AUDI|DIESEL|
| X5 3.0D| BMW|DIESEL|
| 750I| BMW|PETROL|
然後:
//Tokenize
val tokenizer = new Tokenizer().setInputCol("Description").setOutputCol("tokens")
val tokenized = tokenizer.transform(dataframe)
//Creating term-frequency
val htf = new HashingTF().setInputCol(tokenizer.getOutputCol).setOutputCol("rawFeatures").setNumFeatures(500)
val tf = htf.transform(tokenized)
val idf = new IDF().setInputCol("rawFeatures").setOutputCol("features")
// Model & Pipeline
import org.apache.spark.ml.classification.LogisticRegression
val lr = new LogisticRegression().setMaxIter(20).setRegParam(0.01)
import org.apache.spark.ml.Pipeline
val pipeline = new Pipeline().setStages(Array(tokenizer, idf, lr))
//Model
val model = pipeline.fit(dataframe)
錯誤:
java.lang.IllegalArgumentException: Field "rawFeatures" does not exist.
我想通過閱讀說明來預測品牌和燃料類型。
在此先感謝