RMSE test snippet

train_i <- createDataPartition(y=D[1:24, c(geneindex)], times = 1, p=0.7, list=F)

train_data <- D[1:24, c(1, geneindex)][train_i,]
test_data <- D[1:24, c(1, geneindex)][-train_i,]

train_ctrl <- trainControl(
  method='repeatedcv',
  repeats=1, number=1
)

res <- NULL
for (n in 1:8) {
  formula <- bquote(AT2G28890 ~ poly(Time, degree=.(n)))
  lmFit_mock <- train(
    as.formula(formula),
    data=train_data,
    method='lm'
  )
  test_pred <- predict(lmFit_mock, test_data)
  train_pred <- predict(lmFit_mock, train_data)
  test_prs <- postResample(pred = test_pred, obs = test_data$AT2G28890)
  train_prs <- postResample(pred = train_pred, obs = train_data$AT2G28890)
  print(n)
  print(lmFit_mock$results$RMSE)
  print(test_prs['RMSE'])
  res <- bind_rows(res, data.frame(n=n,  train_prs_RMSE=  train_prs['RMSE'], train_cv_RMSE=lmFit_mock$results$RMSE, test_RMSE=test_prs['RMSE']))
}

ggplot(res[1:9,] %>% pivot_longer(-n)) + geom_line(aes(x=n, y=value, color=name))