install.packages("data.table") library(data.table)

subjecttest <- read.table("subject_test.txt") table(subjecttest) subjecttrain <- read.table("subject_train.txt") table(subjecttrain)

y_train <- read.table("y_train.txt") y_test <- read.table("y_test.txt") table(y_train) table(y_test)

X_train <- read.table("X_train.txt") str(X_train) X_test <- read.table("X_test.txt") str(X_test)

subjecttrainDT <- data.table(subjecttrain) is.data.table(subjecttrainDT)

subjecttrainDT[,obsid:=1:7352] subjecttestDT[,obsid:=1:2947] y_trainDT <- data.table(y_train) y_testDT <- data.table(y_test) y_testDT[,obsid:=1:2947] y_trainDT[,obsid:=1:7352] X_trainDT <- data.table(X_train) X_testDT <- data.table(X_test) X_trainDT[,obsid:=1:7352] X_testDT[,obsid:=1:2947]

setkey(subjecttrainDT, obsid) setkey(y_trainDT, obsid) setkey(X_trainDT, obsid) temp <- merge(subjecttrainDT,y_trainDT) setkey(temp, obsid) alldatatrain <- merge(temp,X_trainDT) View(alldatatrain)

setkey(subjecttestDT, obsid) setkey(y_testDT, obsid) setkey(X_testDT, obsid) temp <- merge(subjecttestDT,y_testDT) setkey(temp, obsid) alldatatest <- merge(temp,X_testDT) View(alldatatest)

alldatatrain[,kind:="train"] alldatatest[,kind:="test"] View(alldatatrain) View(alldatatest)

write.csv(alldatatrain,"datatrain.csv") write.csv(alldatatest,"datatest.csv")

resultmeantest <- numeric(ncol(alldatatest)-4) resultSDtest <- numeric(ncol(alldatatest)-4) resultmeantrain <- numeric(ncol(alldatatrain)-4) resultSDtrain <- numeric(ncol(alldatatrain)-4) for(i in 1:(ncol(alldatatest)-4)) { x <- c("V", i) x <- paste(x, collapse = "")