RTutorial-Week1/week1_r_lab_workbook_to_do.Rmd at master · posnerab/RTutorial-Week1 · GitHub

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# R code for the parts of the Lab Workbook
# students needed to create by adapting chunks
# in practice problems and R Lab Workbook R Markdown files


```{r 2 by 2 table for high cholesterol and CHD}

chd_chol_table <- table(wcgs$HighChol0, wcgs$Chd69)
addmargins(chd_chol_table)
round(prop.table(chd_chol_table, 1), digits=3)


```

```{r bmi categories and chd)

wcgs$bmi_cat <- cut(wcgs$BMI0, breaks = c(0, 18.5, 25.0, 30.0, Inf), include.lowest = TRUE, right = FALSE, ordered_results = TRUE, labels = c("underwt", "normal", "overwt", "obese") )

chd_bmi_table <- table(wcgs$bmi_cat, wcgs$Chd69)
addmargins(chd_bmi_table)
round(prop.table(chd_bmi_table, 1), digits=3)

```

```{r smoking at baseline and chd}

chd_smoker_table <- table(wcgs$Smoker0, wcgs$Chd69)
addmargins(chd_smoker_table)
round(prop.table(chd_smoker_table, 1), digits=3)


```

```{r histogram for Weight0 values}

summary(wcgs$Weight0)

ggplot(wcgs, aes(x = Weight0, y = ..density..)) +
  geom_histogram(binwidth = 5, color = "black", fill = "blue") +
  labs(
    title = "WCGS weights at baseline",
    subtitle = "n = 3154 men ages 39 to 59",
    x = "weight in pounds", y = "density" ) +
  scale_x_continuous(limits = c(75, 325)  ,
                     breaks = c(100, 150, 200,  250, 300) ,
                     labels = c(100, 150, 200,  250, 300) ) +
  theme(plot.title = element_text(hjust = 0.5), plot.subtitle = element_text(hjust = 0.5))

```

```{r box plot for Weight0 values}

ggplot(wcgs, aes(y = Weight0) ) +
  geom_boxplot(width = 0.5) +
  scale_x_continuous(labels = NULL) +
  labs(y = "baseline weight in pounds", x = "",
       title = "WCGS weight at baseline",
       subtitle = "n = 3154 men ages 39 to 59") +
  theme(plot.title = element_text(hjust = 0.5), plot.subtitle = element_text(hjust = 0.5))

```
summary(wcgs$Weight0)