Create horizontal boxplot grob

Usage

make_boxplot(
  est,
  lower,
  upper,
  lowhinge,
  uphinge,
  hinge_height = 0.2,
  pch,
  sizes = 1,
  gp = gpar(),
  gp_box = gp,
  t_height = NULL,
  xlim = c(0, 1),
  nudge_y = 0
)

Arguments

est: Median value.
lower: Lower whisker.
upper: Upper whisker.
lowhinge: Lower hinge, a standard whisker will be drawn if this is missing.
uphinge: Upper hinge, a standard whisker will be drawn if this is missing.
hinge_height: Height of the hinge, default is 0.2.
pch: Numeric or character vector indicating what sort of plotting symbol to use. See pointsGrob.
sizes: Size of the point estimation box, can be a vector or a list. The value is a multiple of one line of text, so 1 draws a point as tall as the base_size of the theme. The same scale applies to the summary diamond. Values are used as they are, unless scale_sizes is used to read them as study weights; useful values are roughly between 0.2 and 1.5, and a warning is given when the plot is drawn if they are outside 0.1 to 2.
gp: Graphical parameters of gpar. Please refer to forest_theme for more details.
gp_box: Graphical parameters passed to the hinge, this will be passed to rectGrob. This does not support multiple groups.
t_height: Height of the whisker end vertices. If value is NULL (default), no vertices will be drawn.
xlim: Limits for the x axis as a vector of length 2, i.e. c(low, high).
nudge_y: Horizontal adjustment to nudge groups by, must be within 0 to 1.

Value

A gTree object

Examples

library(grid)

# Function to calculate Box plot values
box_func <- function(x){
  iqr <- IQR(x)
  q3 <- quantile(x, probs = c(0.25, 0.5, 0.75), names = FALSE)
  c("min" = q3[1] - 1.5*iqr, "q1" = q3[1], "med" = q3[2],
    "q3" = q3[3], "max" = q3[3] + 1.5*iqr)
}
# Prepare data
val <- split(ToothGrowth$len, list(ToothGrowth$supp, ToothGrowth$dose))
val <- lapply(val, box_func)

dat <- do.call(rbind, val)
dat <- data.frame(Dose = row.names(dat),
                  dat, row.names = NULL)

dat$Box <- paste(rep(" ", 20), collapse = " ")

# Draw single group box plot
tm <- forest_theme(ci_Theight = 0.2)

p <- forest(dat[,c(1, 7)],
            est = dat$med,
            lower = dat$min,
            upper = dat$max,
            # sizes = sizes,
            fn_ci = make_boxplot,
            ci_column = 2,
            lowhinge = dat$q1,
            uphinge = dat$q3,
            hinge_height = 0.2,
            index_args = c("lowhinge", "uphinge"),
            gp_box = gpar(fill = "black", alpha = 0.4),
            style = tm
)
p


# Multiple group
# Prepare data
dat_oj <- dat[c(1, 3, 5),]
dat_vc <- dat[c(2, 4, 6), ]

dat <- data.frame(Dose = c(0.5, 1, 2))
dat$Box <- paste(rep(" ", 20), collapse = " ")

# Draw plot
tm <- forest_theme(ci_Theight = 0.2,
                   ci_pch = 3)

p <- forest(dat,
            est = list(dat_oj$med, dat_vc$med),
            lower = list(dat_oj$min, dat_vc$min),
            upper = list(dat_oj$max, dat_vc$max),
            fn_ci = make_boxplot,
            ci_column = 2,
            lowhinge = list(dat_oj$q1, dat_vc$q1),
            uphinge = list(dat_oj$q3, dat_vc$q3),
            hinge_height = 0.2,
            index_args = c("lowhinge", "uphinge"),
            style = tm
)

p
#> Warning: Grouped confidence intervals are likely to overlap: a point of `sizes` 0.4 is more than twice the gap between groups. Increase `nudge_y` or reduce `sizes`.

Create horizontal boxplot grob

Usage

Arguments

Value

See also

Examples