Details
Major Description
MLOR do not work correctly when featureStd contains zero.
We can reproduce the bug through such dataset (features including zero variance), will generate wrong result (all coefficients becomes 0)
val multinomialDatasetWithZeroVar = {
val nPoints = 100
val coefficients = Array(
-0.57997, 0.912083, -0.371077,
-0.16624, -0.84355, -0.048509)
val xMean = Array(5.843, 3.0)
val xVariance = Array(0.6856, 0.0) // including zero variance
val testData = generateMultinomialLogisticInput(
coefficients, xMean, xVariance, addIntercept = true, nPoints, seed)
val df = sc.parallelize(testData, 4).toDF().withColumn("weight", lit(1.0))
df.cache()
df
}