70 lines
		
	
	
	
		
			2.5 KiB
		
	
	
	
		
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			70 lines
		
	
	
	
		
			2.5 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
# DLlib Quickstarts
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---
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[Run in Google Colab](https://colab.research.google.com/github/intel-analytics/BigDL/blob/branch-2.0/python/dllib/colab-notebook/dllib_keras_api.ipynb)  [View source on GitHub](https://github.com/intel-analytics/BigDL/blob/branch-2.0/python/dllib/colab-notebook/dllib_keras_api.ipynb)
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---
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**In this guide we will demonstrate how to use _DLlib keras style api_ and _DLlib NNClassifier_ for classification.**
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### **Step 0: Prepare Environment**
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We recommend using [conda](https://docs.conda.io/projects/conda/en/latest/user-guide/install/) to prepare the environment. Please refer to the [install guide](../Overview/chronos.html#install) for more details.
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```bash
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conda create -n my_env python=3.7 # "my_env" is conda environment name, you can use any name you like.
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conda activate my_env
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pip install bigdl-dllib
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```
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### Step 1: Data loading and processing using Spark DataFrame
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```python
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df = spark.read.csv(path, sep=',', inferSchema=True).toDF("num_times_pregrant", "plasma_glucose", "blood_pressure", "skin_fold_thickness", "2-hour_insulin", "body_mass_index", "diabetes_pedigree_function", "age", "class")
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```
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We process the data using Spark API and split the data into train and test set.
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```python
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vecAssembler = VectorAssembler(outputCol="features")
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vecAssembler.setInputCols(["num_times_pregrant", "plasma_glucose", "blood_pressure", "skin_fold_thickness", "2-hour_insulin", "body_mass_index", "diabetes_pedigree_function", "age"])
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train_df = vecAssembler.transform(df)
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changedTypedf = train_df.withColumn("label", train_df["class"].cast(DoubleType())+lit(1))\
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    .select("features", "label")
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(trainingDF, validationDF) = changedTypedf.randomSplit([0.9, 0.1])
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```
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### Step 3: Define classification model using DLlib keras style api
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```python
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x1 = Input(shape=(8,))
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dense1 = Dense(12, activation='relu')(x1)
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dense2 = Dense(8, activation='relu')(dense1)
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dense3 = Dense(2)(dense2)
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model = Model(x1, dense3)
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```
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### Step 4: Create NNClassifier and Fit NNClassifier
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```python
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classifier = NNClassifier(model, CrossEntropyCriterion(), [8]) \
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    .setOptimMethod(Adam()) \
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    .setBatchSize(32) \
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    .setMaxEpoch(150)
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nnModel = classifier.fit(trainingDF)
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```
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### Step 5: Evaluate the trained model
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```python
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predictionDF = nnModel.transform(validationDF).cache()
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predictionDF.sample(False, 0.1).show()
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evaluator = MulticlassClassificationEvaluator(
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    labelCol="label", predictionCol="prediction", metricName="accuracy")
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accuracy = evaluator.evaluate(predictionDF)
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```
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