我正在尝试使用pySpark实现Logistic回归
这是我的代码

from pyspark.mllib.classification import LogisticRegressionWithLBFGS
from time import time
from pyspark.mllib.regression import LabeledPoint
from numpy import array


RES_DIR="/home/shaahmed115/Pet_Projects/DA/TwitterStream_US_Elections/Features/"
sc= SparkContext('local','pyspark')

data_file = RES_DIR + "training.txt"
raw_data = sc.textFile(data_file)

print "Train data size is {}".format(raw_data.count())


test_data_file = RES_DIR + "testing.txt"
test_raw_data = sc.textFile(test_data_file)

print "Test data size is {}".format(test_raw_data.count())

def parse_interaction(line):
    line_split = line.split(",")
    return LabeledPoint(float(line_split[0]), array([float(x) for x in line_split]))

training_data = raw_data.map(parse_interaction)
logit_model = LogisticRegressionWithLBFGS.train(training_data,iterations=10, numClasses=3)


这引发了一个错误:
当前,ML软件包中带有ElasticNet的LogisticRegression仅支持二进制分类。在输入数据集中找到3

以下是我的数据集的示例:
    2,1.0,1.0,1.0
    0,1.0,1.0,1.0
    1,0.0,0.0,0.0

第一个元素是类,其余的是向量。您可以看到有三个类。
有没有变通办法可以使多项式分类与此一起工作?

最佳答案

您看到的错误


  ML软件包中带有ElasticNet的LogisticRegression仅支持二进制
  分类。


清楚了。您可以使用mllib版本支持多项式:
org.apache.spark.mllib.classification.LogisticRegression

/**
 * Train a classification model for Multinomial/Binary Logistic Regression using
 * Limited-memory BFGS. Standard feature scaling and L2 regularization are used by default.
 * NOTE: Labels used in Logistic Regression should be {0, 1, ..., k - 1}
 * for k classes multi-label classification problem.
 *
 * Earlier implementations of LogisticRegressionWithLBFGS applies a regularization
 * penalty to all elements including the intercept. If this is called with one of
 * standard updaters (L1Updater, or SquaredL2Updater) this is translated
 * into a call to ml.LogisticRegression, otherwise this will use the existing mllib
 * GeneralizedLinearAlgorithm trainer, resulting in a regularization penalty to the
 * intercept.
 */

关于python - LogisticRegressionwithLBFGS引发关于不支持多项式分类的错误,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/38961429/

10-12 19:35