#################somente teste de acuracia##########################
index <- createDataPartition(data$resp, p=0.8, list=FALSE)
dataTr <- data %>% slice(index)
dataTest <- data %>% slice(-index)

pc <- prcomp(dataTr[-20692], scale=TRUE, retx=FALSE)
cumVar <- cumsum(pc$sdev^2/sum(pc$sdev^2))
nCompIdeal <- max(2, which.max(cumVar >= 0.95))
dataPcaTr <- as.data.frame(predict(pc, dataTr))[1:nCompIdeal]
dataPcaTr$labels <- dataTr$resp
dataPcaTest <- as.data.frame(predict(pc, dataTest))[1:nCompIdeal]
dataPcaTest$labels <- dataTest$resp

fitLDA <- lda(formula = labels ~ . , data=dataPcaTr)
predLDA_Tr <- predict(fitLDA, dataPcaTr)
(conf <- confusionMatrix(predLDA_Tr$class, dataPcaTr$labels))
predLDA_Te <- predict(fitLDA, dataPcaTest)
(conf <- confusionMatrix(predLDA_Te$class, dataPcaTest$labels))