I am trying to calculae the interval of 'n' days from start date to end date.Function signature would have start_date,end_date, interval as argument which return a map with list of start, end days of given intervals.
Example: start_date:2018-01-01 , End_date : 2018-02-20 interval: 20
Expected Output:
2018-01-01 , 2018-01-20 (20 days)
2018-01-21 , 2018-02-09 (20 days)
2018-02-09 , 2018-01-20 (remaining)
I tried to write in scala but i dont feel it's a proper functional style of writing.
case class DateContainer(period: String, range: (LocalDate, LocalDate))
def generateDates(startDate: String, endDate: String,interval:Int): Unit = {
import java.time._
var lstDDateContainer = List[DateContainer]()
var start = LocalDate.parse(startDate)
val end = LocalDate.parse(endDate)
import java.time.temporal._
var futureMonth = ChronoUnit.DAYS.addTo(start, interval)
var i = 1
while (end.isAfter(futureMonth)) {
lstDDateContainer = DateContainer("P" + i, (start, futureMonth)):: lstDDateContainer
start=futureMonth
futureMonth = ChronoUnit.DAYS.addTo(futureMonth, interval)
i += 1
}
lstDDateContainer= DateContainer("P" + i, (start, end))::lstDDateContainer
lstDDateContainer.foreach(println)
}
generateDates("2018-01-01", "2018-02-20",20)
Could anyone help me to write in a functional style.
I offer a solution that produces a slightly different result than given in the question but could be easily modified to get the desired answer:
//Preliminaries
val fmt = DateTimeFormatter.ofPattern("yyyy-MM-dd")
val startDate ="2018-01-01"
val endDate = "2018-02-21"
val interval = 20L
val d1 = LocalDate.parse(startDate, fmt)
val d2 = LocalDate.parse(endDate, fmt)
//The main code
Stream.continually(interval)
.scanLeft((d1, d1.minusDays(1), interval)) ((x,y) => {
val finDate = x._2.plusDays(y)
if(finDate.isAfter(d2))
(x._2.plusDays(1), d2, ChronoUnit.DAYS.between(x._2, d2))
else
(x._2.plusDays(1), x._2.plusDays(y), y)
}).takeWhile(d => d._3 > 0).drop(1).toList
Result:
(2018-01-01,2018-01-20,20)
(2018-01-21,2018-02-09,20)
(2018-02-10,2018-02-21,12)
The idea is to scan a 3-tuple through a stream of interval and stop when no more days are remaining.
Use the java.time library to generate the dates and Stream.iterate() to generate the sequence of intervals.
import java.time.LocalDate
def generateDates( startDate :LocalDate
, endDate :LocalDate
, dayInterval :Int ) :Unit = {
val intervals =
Stream.iterate((startDate, startDate plusDays dayInterval-1)){
case (_,lastDate) =>
val nextDate = lastDate plusDays dayInterval
(lastDate plusDays 1, if (nextDate isAfter endDate) endDate
else nextDate)
}.takeWhile(_._1 isBefore endDate)
println(intervals.mkString("\n"))
}
usage:
generateDates(LocalDate.parse("2018-01-01"), LocalDate.parse("2018-02-20"), 20)
// (2018-01-01,2018-01-20)
// (2018-01-21,2018-02-09)
// (2018-02-10,2018-02-20)
Something like (Untested):
def dates(startDate: LocalDate, endDate: LocalDate, dayInterval: Int): List[(LocalDate, LocalDate, Int)] = {
if(startDate.isAfter(endDate)) {
Nil
}
else {
val nextStart = startDate.plusDays(dayInterval)
if(nextStart.isAfter(startDate)) {
List((startDate, endDate, ChronoUnit.DAYS.between(startDate, endDate)))
}
else {
(startDate, nextStart, dayInterval) :: dates(nextStart, endDate, dayInterval)
}
}
}
If your'e open to using Joda for date-time manipulations, here's what I use
import org.joda.time.{DateTime, Days}
// given from & to dates, find no of days elapsed in between (integer)
def getDaysInBetween(from: DateTime, to: DateTime): Int = Days.daysBetween(from, to).getDays
def getDateSegments(from: DateTime, to: DateTime, interval: Int): Seq[(DateTime, DateTime)] = {
// no of days between from & to dates
val days: Int = DateTimeUtils.getDaysInBetween(from, to) + 1
// no of segments (date ranges) between to & from dates
val segments: Int = days / interval
// (remaining) no of days in last range
val remainder: Int = days % interval
// last date-range
val remainderRanges: Seq[(DateTime, DateTime)] =
if (remainder != 0) from -> from.plusDays(remainder - 1) :: Nil
else Nil
// all (remaining) date-ranges + last date-range
(0 until segments).map { segment: Int =>
to.minusDays(segment * interval + interval - 1) -> to.minusDays(segment * interval)
} ++ remainderRanges
}
I'm trying out to generate a simple ALS model using the spark documentation here.
My first file(ratings.csv) has 20million UserID,MovID,Rat and can be downloaded here
So I have the testing data which is a subset of ratings.csv. That test dataset can be downloaded here:
The test file has just the UserID, Movie ID column.
So to create training data we will have to filter ratings.csv.
The following code is working fine for a smaller case of 100,000 UserID,MovID rating. I am not able to generate the model for the big case.
Please help with a pointer.
/**
* Created by echoesofconc on 3/8/17.
*/
import org.apache.spark.SparkConf
import org.apache.spark.SparkContext
import org.apache.spark.rdd.RDD
import org.apache.spark.mllib.recommendation.ALS
import org.apache.spark.mllib.recommendation.MatrixFactorizationModel
import org.apache.spark.mllib.recommendation.Rating
import java.io._
import scala.collection.mutable.ListBuffer
object Prateek_Agrawal_task1 {
def dropheader(data: RDD[String]): RDD[String] = {
data.mapPartitionsWithIndex((idx, lines) => {
if (idx == 0) {
lines.drop(1)
}
lines
})
}
def create_training(ratings_split: RDD[Array[String]], ratings_testing: Array[Array[String]]) = {
ratings_split.filter(x => {
ratings_testing.exists(y =>
(x(0) == y(0) && x(1) == y(1))
) == false
})
}
def create_testing(ratings_split: RDD[Array[String]], ratings_testing: Array[Array[String]]) = {
ratings_split.filter(x => {
ratings_testing.exists(y =>
(x(0) == y(0) && x(1) == y(1))
) == true
})
}
def create_model(ratings_train:RDD[Array[String]],rank:Int,numIterations:Int ):org.apache.spark.mllib.recommendation.MatrixFactorizationModel={
val ratings = ratings_train.map(_ match { case Array(user,item,rate,temp) =>
Rating(user.toInt, item.toInt, rate.toDouble)
})
val model = ALS.train(ratings, rank, numIterations, 0.01)
return model
}
def print_results(final_predictions_adjusted:RDD[((Int, Int), Double)])={
val rating_range=final_predictions_adjusted.map(x=>(x._2.toInt,1)).reduceByKey(_+_).sortByKey()
val rating_range_till_4=rating_range.map{x=>
var temp=x
if (x._1==5){temp=(4,x._2)}
temp
}.reduceByKey(_+_)
rating_range_till_4.sortByKey().foreach { x =>
if(x._1==0)
printf(">=0 and <1: " + x._2+"\n")
if(x._1==1)
printf(">=1 and <2: " + x._2+"\n")
if(x._1==2)
printf(">=2 and <3: " + x._2+"\n")
if(x._1==3)
printf(">=3 and <4: " + x._2+"\n")
if(x._1==4)
printf(">=4 " + x._2+"\n")
if(x._1==5)
printf("=5 " + x._2+"\n")
}
}
case class User_mov_rat(UserID: Int, MovieID:Int, Pred_rating: Double)
def print_outputfile(final_predictions_adjusted:RDD[((Int, Int), Double)])={
val writer = new FileWriter(new File("./output.txt" ))
writer.write("UserID,MovieID,Pred_rating\n")
final_predictions_adjusted.collect().foreach(x=>{writer.write(x._1._1+","+x._1._2+","+x._2+"\n")})
writer.close()
}
def main(args: Array[String]): Unit = {
val conf = new SparkConf().setAppName("Prateek_Agrawal_task1").setMaster("local[2]")
val sc = new SparkContext(conf)
val file = "/Users/echoesofconc/Documents/USC_courses/INF553/ml-20m/ratings.csv"
val test = "/Users/echoesofconc/Documents/USC_courses/INF553/Prateek_Agrawal_hw3/testing_20m.csv"
val data = sc.textFile(file, 2).cache()
val data_test = sc.textFile(test, 2).cache()
// Drop Header
val data_wo_header=dropheader(data).persist()
val data_test_wo_header=dropheader(data_test).persist()
// Create Training and testing data of the format (User ID, MovID, Rating, Time)
val ratings_split = data_wo_header.map(line => line.split(",")).persist()
data_wo_header.unpersist()
data.unpersist()
val ratings_testing = data_test_wo_header.map(line => line.split(",")).collect()
data_test_wo_header.unpersist()
data_test.unpersist()
val ratings_train = create_training(ratings_split, ratings_testing).persist()
val ratings_test=create_testing(ratings_split, ratings_testing)
ratings_split.unpersist()
ratings_test.unpersist()
// Create the model using rating_train the training data
val rank = 1
val numIterations = 10
val model=create_model(ratings_train,rank,numIterations)
ratings_train.unpersist()
// Average user,Rating from training this is for cases which are there in test but not rated by any user in training
val user_avgrat=ratings_test.map(_ match { case Array(user, mov, rate, temp) =>(user.toInt, (rate.toDouble,1.0))}).reduceByKey((x,y)=>(x._1 + y._1, x._2 + y._2)).mapValues{ case (sum, count) => (1.0 * sum) / count }
// Predict user_mov ratings
val user_mov = data_test_wo_header.map(_.split(',') match { case Array(user, mov) =>
(user.toInt,mov.toInt)
})
val predictions =
model.predict(user_mov).map { case Rating(user, mov, rate) =>
((user, mov), rate)
}
// Combine Predictions and unpredicted user,Movies due to them being individual. Going forward we need to improve the accuracy for these predictions
val user_mov_rat=user_mov.map(x=>(x,0.0))
val predictions_unpredicted_combined= predictions.union(user_mov_rat).reduceByKey(_+_).map(x=>(x._1._1,(x._1._2,x._2)))
// Combine average rating and predictions+unpredicted values
val avg_rating_predictions_unpredicted_combined=predictions_unpredicted_combined.join(user_avgrat)
// Generate final predictions RDD
val final_predictions=avg_rating_predictions_unpredicted_combined.map{x=>
var temp=((x._1,x._2._1._1),x._2._2)
if(x._2._1._2==0.0){temp=((x._1,x._2._1._1),x._2._2)}
if(x._2._1._2!=0.0){temp=((x._1,x._2._1._1),x._2._1._2)}
temp
}
// Adjust for ratings above 5.0 and below 0.0
val final_predictions_adjusted=final_predictions.map{x=>
var temp=x
if (x._2>5.0){temp=(x._1,5.0)}
if (x._2<0.0){temp=(x._1,0.0)}
temp
}
val ratesAndPreds = ratings_test.map(_ match { case Array(user, mov, rate, temp) => ((user.toInt,mov.toInt),rate.toDouble)}).join(final_predictions_adjusted)
val MSE = ratesAndPreds.map { case ((user, product), (r1, r2)) =>
val err = (r1 - r2)
err * err
}.mean()
val RMSE=math.sqrt(MSE)
// Print output.txt
print_outputfile(final_predictions_adjusted)
// Print the predictionresults
print_results(final_predictions_adjusted.sortByKey())
print(RMSE+"\n")
}
}
In case someone thinks I should be doing a regex match I have tried that approach. BUt that dosen't seem to be a bottleneck.
I only need to complete the create model part on which I am stuck for the big dataset. Can somebody help.
EDIT:
Another approach I tried which is much faster by using broadcast variables. But it's been running for 12 hrs with no signs of progress. On spark UI somehow the whole of the RDD(ratings.csv ~500MB) is not cached. Only around 64MB with 2.5 Million lines is being processed initially. I am using --executor-memory -8g. I have modified the create_training create_testing functions:
/**
* Created by echoesofconc on 3/8/17.
*/
import org.apache.spark.SparkConf
import org.apache.spark.SparkContext
import org.apache.spark.rdd.RDD
import org.apache.spark.mllib.recommendation.ALS
import org.apache.spark.mllib.recommendation.Rating
import java.io._
object Prateek_Agrawal_task2 {
def dropheader(data: RDD[String]): RDD[String] = {
data.mapPartitionsWithIndex((idx, lines) => {
if (idx == 0) {
lines.drop(1)
}
lines
})
}
def create_training(data_wo_header: RDD[String], data_test_wo_header: RDD[String],sc:SparkContext): RDD[String] = {
val rdd2array = sc.broadcast(data_test_wo_header.collect())
val training_set = data_wo_header.filter{
case(x) => rdd2array.value.filter(y => x.indexOf(y.toString())==0).length == 0
}
return training_set
}
def create_test(data_wo_header: RDD[String], data_test_wo_header: RDD[String],sc:SparkContext): RDD[String] = {
val rdd2array = sc.broadcast(data_test_wo_header.collect())
val training_set = data_wo_header.filter{
case(x) => rdd2array.value.filter(y => x.indexOf(y.toString())==0).length != 0
}
return training_set
}
def create_model(ratings_train:RDD[String],rank:Int,numIterations:Int ):org.apache.spark.mllib.recommendation.MatrixFactorizationModel={
val ratings = ratings_train.map(_.split(',') match { case Array(user, item, rate, timestamp) =>
Rating(user.toInt, item.toInt, rate.toDouble)
})
val model = ALS.train(ratings, rank, numIterations, 0.01)
return model
}
def print_results(final_predictions_adjusted:RDD[((Int, Int), Double)])={
val rating_range=final_predictions_adjusted.map(x=>(x._2.toInt,1)).reduceByKey(_+_).sortByKey()
val rating_range_till_4=rating_range.map{x=>
var temp=x
if (x._1==5){temp=(4,x._2)}
temp
}.reduceByKey(_+_)
rating_range_till_4.sortByKey().foreach { x =>
if(x._1==0)
printf(">=0 and <1: " + x._2+"\n")
if(x._1==1)
printf(">=1 and <2: " + x._2+"\n")
if(x._1==2)
printf(">=2 and <3: " + x._2+"\n")
if(x._1==3)
printf(">=3 and <4: " + x._2+"\n")
if(x._1==4)
printf(">=4 " + x._2+"\n")
if(x._1==5)
printf("=5 " + x._2+"\n")
}
}
case class User_mov_rat(UserID: Int, MovieID:Int, Pred_rating: Double)
def print_outputfile(final_predictions_adjusted:RDD[((Int, Int), Double)])={
val writer = new FileWriter(new File("./output.txt" ))
writer.write("UserID,MovieID,Pred_rating\n")
final_predictions_adjusted.collect().foreach(x=>{writer.write(x._1._1+","+x._1._2+","+x._2+"\n")})
writer.close()
}
def main(args: Array[String]): Unit = {
val conf = new SparkConf().setAppName("Prateek_Agrawal_task1").setMaster("local[2]")
val sc = new SparkContext(conf)
val file = "/Users/echoesofconc/Documents/USC_courses/INF553/ml-latest-small/ratings.csv"
val test = "/Users/echoesofconc/Documents/USC_courses/INF553/Prateek_Agrawal_hw3/testing_small.csv"
// val file = "/Users/echoesofconc/Documents/USC_courses/INF553/ml-20m/ratings.csv"
// val test = "/Users/echoesofconc/Documents/USC_courses/INF553/Prateek_Agrawal_hw3/testing_20m.csv"
val data = sc.textFile(file, 2).persist()
val data_test = sc.textFile(test, 2).persist()
// Drop Header
val data_wo_header=dropheader(data)
val data_test_wo_header=dropheader(data_test)
// Create Traing and testing data of the format (User ID, MovID, Rating, Time)
val ratings_train=create_training(data_wo_header,data_test_wo_header,sc).persist()
val ratings_test=create_test(data_wo_header,data_test_wo_header,sc)
// val ratings_test=create_test(data_wo_header,data_test_wo_header,sc)
// data_test_wo_header.unpersist()
// data_test.unpersist()
//// data.unpersist()
//// data_test.unpersist()
// Create the model using rating_train the training data
val rank = 1
val numIterations = 10
val model=create_model(ratings_train,rank,numIterations)
// ratings_train.unpersist()
// model.save(sc, "target/tmp/myCollaborativeFilter")
// val Model = MatrixFactorizationModel.load(sc, "/Users/echoesofconc/myCollaborativeFilter")
// Average user,Rating from training
val user_avgrat=ratings_test.map(_.split(",") match { case Array(user, mov, rate, temp) =>(user.toInt, (rate.toDouble,1.0))}).reduceByKey((x,y)=>(x._1 + y._1, x._2 + y._2)).mapValues{ case (sum, count) => (1.0 * sum) / count }
//data
// Predict user_mov ratings
val user_mov = data_test_wo_header.map(_.split(',') match { case Array(user, mov) =>
(user.toInt,mov.toInt)
})
val predictions =
model.predict(user_mov).map { case Rating(user, mov, rate) =>
((user, mov), rate)
}
// Combine Predictions and unpredicted user,Movies due to them being individual. Going forward we need to improve the accuracy for these predictions
val user_mov_rat=user_mov.map(x=>(x,0.0))
val predictions_unpredicted_combined= predictions.union(user_mov_rat).reduceByKey(_+_).map(x=>(x._1._1,(x._1._2,x._2)))
// Combine average rating and predictions+unpredicted values
val avg_rating_predictions_unpredicted_combined=predictions_unpredicted_combined.join(user_avgrat)
// Generate final predictions RDD
val final_predictions=avg_rating_predictions_unpredicted_combined.map{x=>
var temp=((x._1,x._2._1._1),x._2._2)
if(x._2._1._2==0.0){temp=((x._1,x._2._1._1),x._2._2)}
if(x._2._1._2!=0.0){temp=((x._1,x._2._1._1),x._2._1._2)}
temp
}
// Adjust for ratings above 5.0 and below 0.0
val final_predictions_adjusted=final_predictions.map{x=>
var temp=x
if (x._2>5.0){temp=(x._1,5.0)}
if (x._2<0.0){temp=(x._1,0.0)}
temp
}
val ratesAndPreds = ratings_test.map(_.split(",") match { case Array(user, mov, rate, temp) => ((user.toInt,mov.toInt),rate.toDouble)}).join(final_predictions_adjusted)
val MSE = ratesAndPreds.map { case ((user, product), (r1, r2)) =>
val err = (r1 - r2)
err * err
}.mean()
val RMSE=math.sqrt(MSE)
// Print output.txt
print_outputfile(final_predictions_adjusted)
// Print the predictionresults
print_results(final_predictions_adjusted.sortByKey())
print(RMSE+"\n")
}
}
This worked out to be fine. It's using join to create testng training data
/**
* Created by echoesofconc on 3/8/17.
*/
import org.apache.spark.SparkConf
import org.apache.spark.SparkContext
import org.apache.spark.rdd.RDD
import org.apache.spark.mllib.recommendation.ALS
import org.apache.spark.mllib.recommendation.Rating
import org.apache.spark.mllib.recommendation.MatrixFactorizationModel
import java.io._
object Prateek_Agrawal_task1 {
def dropheader(data: RDD[String]): RDD[String] = {
data.mapPartitionsWithIndex((idx, lines) => {
if (idx == 0) {
lines.drop(1)
}
lines
})
}
def create_training(ratings_split: RDD[Array[String]], ratings_testing: Array[Array[String]]) = {
ratings_split.filter(x => {
ratings_testing.exists(y =>
(x(0) == y(0) && x(1) == y(1))
) == false
})
}
def create_testing(ratings_split: RDD[Array[String]], ratings_testing: Array[Array[String]]) = {
ratings_split.filter(x => {
ratings_testing.exists(y =>
(x(0) == y(0) && x(1) == y(1))
) == true
})
}
def create_model(ratings_train:RDD[((String, String), (String, String))],rank:Int,numIterations:Int ):org.apache.spark.mllib.recommendation.MatrixFactorizationModel={
val ratings = ratings_train.map(_ match { case ((user,item),(rate,temp)) =>
Rating(user.toInt, item.toInt, rate.toDouble)
})
val model = ALS.train(ratings, rank, numIterations, 0.01)
return model
}
def print_results(final_predictions_adjusted:RDD[((Int, Int), Double)])={
val rating_range=final_predictions_adjusted.map(x=>(x._2.toInt,1)).reduceByKey(_+_).sortByKey()
val rating_range_till_4=rating_range.map{x=>
var temp=x
if (x._1==5){temp=(4,x._2)}
temp
}.reduceByKey(_+_)
rating_range_till_4.sortByKey().foreach { x =>
if(x._1==0)
printf(">=0 and <1: " + x._2+"\n")
if(x._1==1)
printf(">=1 and <2: " + x._2+"\n")
if(x._1==2)
printf(">=2 and <3: " + x._2+"\n")
if(x._1==3)
printf(">=3 and <4: " + x._2+"\n")
if(x._1==4)
printf(">=4 " + x._2+"\n")
if(x._1==5)
printf("=5 " + x._2+"\n")
}
}
case class User_mov_rat(UserID: Int, MovieID:Int, Pred_rating: Double)
def print_outputfile(final_predictions_adjusted:RDD[((Int, Int), Double)])={
val writer = new FileWriter(new File("./output.txt" ))
writer.write("UserID,MovieID,Pred_rating\n")
final_predictions_adjusted.collect().foreach(x=>{writer.write(x._1._1+","+x._1._2+","+x._2+"\n")})
writer.close()
}
def main(args: Array[String]): Unit = {
val conf = new SparkConf().setAppName("Prateek_Agrawal_task1").setMaster("local[2]")
val sc = new SparkContext(conf)
// val file = "/Users/echoesofconc/Documents/USC_courses/INF553/ml-latest-small/ratings.csv"
// val test = "/Users/echoesofconc/Documents/USC_courses/INF553/Prateek_Agrawal_hw3/testing_small.csv"
val file = "/Users/echoesofconc/Documents/USC_courses/INF553/ml-20m/ratings.csv"
val test = "/Users/echoesofconc/Documents/USC_courses/INF553/Prateek_Agrawal_hw3/testing_20m.csv"
val data = sc.textFile(file, 2).cache()
val data_test = sc.textFile(test, 2).cache()
// Drop Header
// val data_wo_header=dropheader(data).persist()
// val data_test_wo_header=dropheader(data_test).persist()
// Create Traing and testing data of the format (User ID, MovID, Rating, Time)
val data_wo_header=dropheader(data).map(_.split(",")).map(x=>((x(0),x(1)),(x(2),x(3))))
val data_test_wo_header=dropheader(data_test).map(_.split(",")).map(x=>((x(0),x(1)),1))
val ratings_train=data_wo_header.subtractByKey(data_test_wo_header)
val ratings_test=data_wo_header.subtractByKey(ratings_train)
data_test_wo_header.unpersist()
data_wo_header.unpersist()
data.unpersist()
data_test.unpersist()
// val ratings_split = data_wo_header.map(line => line.split(",")).persist()
// data_wo_header.unpersist()
// data.unpersist()
// val ratings_testing = data_test_wo_header.map(line => line.split(",")).collect()
// data_test_wo_header.unpersist()
// data_test.unpersist()
//
// val ratings_train = create_training(ratings_split, ratings_testing).persist()
// val ratings_test=create_testing(ratings_split, ratings_testing)
// ratings_split.unpersist()
// ratings_test.unpersist()
// Create the model using rating_train the training data
val rank = 1
val numIterations = 10
// val model=create_model(ratings_train,rank,numIterations)
//
// model.save(sc, "/Users/echoesofconc/Documents/USC_courses/INF553/Prateek_Agrawal_hw3/myCollaborativeFilter")
val model = MatrixFactorizationModel.load(sc, "/Users/echoesofconc/Documents/USC_courses/INF553/Prateek_Agrawal_hw3/myCollaborativeFilter")
// Average user,Rating from training
val user_avgrat=ratings_train.map(_ match { case ((user, mov), (rate, temp)) =>(user.toInt, (rate.toDouble,1.0))}).reduceByKey((x,y)=>(x._1 + y._1, x._2 + y._2)).mapValues{ case (sum, count) => (1.0 * sum) / count }
ratings_train.unpersist()
// Predict user_mov ratings
val user_mov = data_test_wo_header.map(_ match { case ((user, mov),temp) =>
(user.toInt,mov.toInt)
})
val predictions =
model.predict(user_mov).map { case Rating(user, mov, rate) =>
((user, mov), rate)
}
// Combine Predictions and unpredicted user,Movies due to them being individual. Going forward we need to improve the accuracy for these predictions
val user_mov_rat=user_mov.map(x=>(x,0.0))
val predictions_unpredicted_combined= predictions.union(user_mov_rat).reduceByKey(_+_).map(x=>(x._1._1,(x._1._2,x._2)))
// Combine average rating and predictions+unpredicted values
val avg_rating_predictions_unpredicted_combined=predictions_unpredicted_combined.join(user_avgrat)
// Generate final predictions RDD
val final_predictions=avg_rating_predictions_unpredicted_combined.map{x=>
var temp=((x._1,x._2._1._1),x._2._2)
if(x._2._1._2==0.0){temp=((x._1,x._2._1._1),x._2._2)}
if(x._2._1._2!=0.0){temp=((x._1,x._2._1._1),x._2._1._2)}
temp
}
// Adjust for ratings above 5.0 and below 0.0
val final_predictions_adjusted=final_predictions.map{x=>
var temp=x
if (x._2>5.0){temp=(x._1,5.0)}
if (x._2<0.0){temp=(x._1,0.0)}
temp
}
// final_predictions_adjusted.count()
val ratesAndPreds_map = ratings_test.map(_ match { case ((user, mov), (rate, temp)) => ((user.toInt,mov.toInt),rate.toDouble)})
val ratesAndPreds=ratesAndPreds_map.join(final_predictions_adjusted)
val MSE = ratesAndPreds.map { case ((user, product), (r1, r2)) =>
val err = (r1 - r2)
err * err
}.mean()
val RMSE=math.sqrt(MSE)
// Print output.txt
print_outputfile(final_predictions_adjusted)
// Print the predictionresults
print_results(final_predictions_adjusted.sortByKey())
print(RMSE+"\n")
}
}
I am new for scala as well as FOR spark, Please help me to resolve this issue.
in spark shell when I load below functions individually they run without any exception, when I copy this function in scala object, and load same file in spark shell they throws task not serialization exception in "processbatch" function when trying to parallelize.
PFB code for the same:
import org.apache.spark.sql.Row
import org.apache.log4j.Logger
import org.apache.spark.sql.hive.HiveContext
object Process {
val hc = new HiveContext(sc)
def processsingle(wait: Int, patient: org.apache.spark.sql.Row, visits: Array[org.apache.spark.sql.Row]) : String = {
var out = new StringBuilder()
val processStart = getTimeInMillis()
for( x <- visits ) {
out.append(", " + x.getAs("patientid") + ":" + x.getAs("visitid"))
}
}
def processbatch(batch: Int, wait: Int, patients: Array[org.apache.spark.sql.Row], visits: Array[org.apache.spark.sql.Row]) = {
val out = sc.parallelize(patients, batch).map( r=> processsingle(wait, r, visits.filter(f=> f.getAs("patientid") == r.getAs("patientid")))).collect()
for(x <- out) println(x)
}
def processmeasures(fetch: Int, batch: Int, wait: Int) = {
val patients = hc.sql("SELECT patientid FROM tableName1 order by p_id").collect()
val visit = hc.sql("SELECT patientid, visitid FROM tableName2")
val count = patients.length
val fetches = if(count % fetch > 0) (count / fetch + 1) else (count / fetch)
for(i <- 0 to fetches.toInt-1){
val startFetch = i*fetch
val endFetch = math.min((i+1)*fetch, count.toInt)-1
val fetchSize = endFetch - startFetch + 1
val fetchClause = "patientid >= " + patients(startFetch).get(0) + " and patientid <= " + patients(endFetch).get(0)
val fetchVisit = visit.filter( fetchClause ).collect()
val batches = if(fetchSize % batch > 0) (fetchSize / batch + 1) else (fetchSize / batch)
for(j <- 0 to batches.toInt-1){
val startBatch = j*batch
val endBatch = math.min((j+1)*batch, fetch.toInt)-1
println(s"Batch from $startBatch to $endBatch");
val batchVisits = fetchVisit.filter(g => g.getAs[Long]("patientid") >= patients(i*fetch + startBatch).getLong(0) && g.getAs[Long]("patientid") <= patients(math.min(i*fetch + endBatch + 1, endFetch)).getLong(0))
processbatch(batch, wait, patients.slice(i*fetch + startBatch, i*fetch + endBatch + 1), batchVisits)
}
}
println("Processing took " + getExecutionTime(processStart) + " millis")
}
}
You should make Process object Serializable:
object Process extends Serializable {
...
}