hw5

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library(dplyr) library(gt) library(tidymodels) library(stringr)

install.packages(“ISLR2”) library(ISLR2)

data(Smarket)

Create training data

train_data <- Smarket %>% filter(Year < 2005)

Fit LDA model

lda_fit <- MASS::lda(Direction ~ Lag1 + Lag2, data = train_data)

Predict on test data

test_data <- Smarket %>% filter(Year == 2005) lda_pred <- predict(lda_fit, test_data)

Confusion matrix

conf_matrix <- table(lda_pred\(class, test_data\)Direction)

Convert to gt table

conf_matrix %>% as.data.frame() %>% rename(Predicted = Var1, Actual = Var2, Count = Freq) %>% tidyr::pivot_wider(names_from = Actual, values_from = Count) %>% gt()

as.data.frame(lda_pred$posterior) %>% slice(1:5) %>% gt()

qda_fit <- MASS::qda(Direction ~ Lag1 + Lag2, data = train_data) qda_pred <- predict(qda_fit, test_data)

table(qda_pred\(class, test_data\)Direction) %>% as.data.frame() %>% rename(Predicted = Var1, Actual = Var2, Count = Freq) %>% tidyr::pivot_wider(names_from = Actual, values_from = Count) %>% gt()