Add w10 code

week10/index.qmd

@@ -30,5 +30,13 @@ schedule |>
 ```{r}
 #| output: asis
 show_slides(week)
+```
+
+## Lab code
+
+Lab code can be downloaded here: [`lab.R`](lab.R)
+
+```{r}
+#| output: asis
 show_assignments(week)
 ```

week10/lab.R

@@ -0,0 +1,205 @@
+library(rlang)
+parse_expr("seq(1,10,       by = 0.5)")
+parse_expr("data |> mutate()")
+parse_expr("data %>% mutate()")
+
+
+myseq <- parse_expr("seq(1,10,       by = 0.5)")
+class(myseq)
+new_function(list(), myseq)
+eval(myseq)
+
+mycalc <- parse_expr("5 + 3 * 7")
+
+as.list(mycalc)
+
+5 + (3 * 7)
+
+
+as.list(mycalc[[3]])
+
+as.list(mycalc)
+mycalc[[2]] <- 10
+mycalc
+
+parse_expr("`+`(5, 3*7)")
+parse_expr("`+`(5, `*`(3,7))")
+
+mycalc
+lobstr::ast(mycalc)
+lobstr::ast(5 + 3 * 7)
+as.list(mycalc)
+
+
+lobstr::ast(
+  mtcars |>
+    group_by(cyl) |>
+    filter(mpg > 0.2) |>
+    mutate(mpg/wt) |>
+    ggplot()
+)
+
+parse_expr(
+"mtcars |>
+  group_by(cyl) |>
+  filter(mpg > 0.2) |>
+  mutate(mpg/wt) |>
+  ggplot()"
+)
+
+lobstr::ast((-2)^2)
+(-2)^2
+
+lobstr::ast(!countries %in% c("Australia", "China"))
+
+
+as.list(myseq)
+call2("seq", 1L, 10, by = 0.5)
+parse_expr(sprintf("seq(%i,%i, by = %f)", 1L, 10, 0.5))
+
+
+x / y
+x <- expr(3 + 6)
+y <- expr(1 + 2)
+
+call2("/", x, y)
+parse_expr(sprintf("%s / %s", "3 + 6", "1 + 2"))
+
+
+with(
+  list(
+    `+` = base::`-`,
+    `-` = base::`+`
+  ),
+  3 + 8
+)
+
+library(rlang)
+pkgs <- "rlang"
+library(pkgs)
+
+purrr::map(
+  c("ggplot2", "dplyr", "tidyr"),
+  library,
+  character.only = TRUE
+)
+
+purrr::map(
+  c("ggplot2", "dplyr", "tidyr"),
+  call2, .fn = "library"
+) |>
+  purrr::map(eval)
+
+
+library("ggplot2")
+
+mtcars |> select(cyl)
+cyl
+
+readr::read_csv("data/study.csv")
+
+ggplot(mtcars, aes(mpg, wt)) +
+  geom_point()
+
+ggplot2:::`+.gg`
+mpg
+wt
+
+mtcars |>
+  mutate(wt/hp)
+
+
+mtcars |>
+  left_join(mpg, by = c("model" = "car"))
+
+join_by
+
+1 + 1
+
+base::`+`
+
+eval(sym("pi"))
+sym("pi")
+sym("mpg")
+expr(1/pi)
+lobstr::ast(1/pi)
+quo(1/pi)
+eval_tidy(quo(1/pi))
+
+function(expr) {
+  expr <- enexpr(expr)
+}
+
+
+call2(sym("mutate"), sym("mtcars"),  expr(wt/sym("hp")))
+
+"mutate"()
+
+sym("2 * pi")
+
+mtcars |>
+  mutate(2 * mpg) |>
+  select("2 * mpg")
+
+expr(2 * pi)
+lobstr::ast(2*pi)
+
+quo(2 * pi)
+
+
+capture_expr <- function(x) {
+  x <- enquo(x)
+  pi <- 2.29
+  eval_tidy(x)
+}
+
+capture_expr(2*pi)
+# expr(2*pi)
+
+myseq
+lobstr::ast(myseq)
+lobstr::ast(!!myseq)
+
+expr(!!pi)
+expr(1/pi)
+expr(1/!!pi)
+
+wt <- rnorm(32)
+mtcars |>
+  summarise(weighted.mean(mpg, !!wt))
+
+cyl <- 4
+mtcars |>
+  filter(cyl == !!cyl)
+
+var_summary(mtcars, cyl)
+
+syms(c("a", "b"))
+exprs(a+b, a-b)
+quos(a+b, a-b)
+
+var_summaries <- function(data, ...) {
+  vars <- enquos(...)
+  .min <- purrr::map(vars, ~ expr(min(!!.)))
+  names(.min) <- c("a", "b")
+  .max <- purrr::map(vars, ~ expr(max(!!.)))
+  data |>
+    summarise(n = n(), !!!.min, !!!.max)
+    # summarise(n = n(), a = min(mpg), b = min(wt), !!!.max)
+}
+mtcars |>
+  group_by(cyl) |>
+  var_summaries(mpg, wt)
+
+
+
+cyl <- 4
+mtcars |>
+  filter(cyl == !!cyl)
+mtcars |>
+  filter(.data$pi == .env$cyl)
+
+mtcars |>
+  filter(.data$pi == .env$cyl)
+
+pi