guide_coloursteps2 #' @param title A title for the guide.

guide_coloursteps2 #' @param title A title for the guide.

guide_coloursteps2(
  title = waiver(),
  theme = NULL,
  alpha = NA,
  even.steps = TRUE,
  show.limits = NULL,
  direction = NULL,
  reverse = FALSE,
  order = 0,
  available_aes = c("colour", "color", "fill"),
  barheight = unit(0.9, "npc"),
  ...
)

guide_colorsteps2(
  title = waiver(),
  theme = NULL,
  alpha = NA,
  even.steps = TRUE,
  show.limits = NULL,
  direction = NULL,
  reverse = FALSE,
  order = 0,
  available_aes = c("colour", "color", "fill"),
  barheight = unit(0.9, "npc"),
  ...
)

Arguments

theme

A theme object for rendering the guide.

alpha

Alpha transparency level.

even.steps

Logical; should the steps be evenly spaced?

show.limits

Logical; should the limits be shown?

direction

Direction of the guide ("horizontal" or "vertical").

reverse

Logical; should the guide be reversed?

order

Order of the guide.

available_aes

Available aesthetics for this guide.

barheight

Height of the color bar. Deprecated in ggplot2 3.5.0.

...

Additional arguments passed to the guide.

Examples

library(rcolors)
library(ggplot2)
library(magrittr)

df = data.frame(x = 1:10, y = 1:10, z = 1:10)

brks <- c(2, 4, 6, 8) %>% c(-Inf, ., Inf) # 这里要包含
nbrk <- length(brks) - 1
cols = get_color(rcolors$amwg256, nbrk)

ggplot(df, aes(x, y, z = x)) +
  stat_levels(aes(color = after_stat(level)), breaks = brks, geom = "point") +
  scale_color_manual(
    values = cols,
    guide = guide_coloursteps2(title = "lgd", barheight = unit(0.8, "npc"))
  ) +
  guides(fill = "none")


## another option: use `scale_color_stepsn`
# example 2
# NOTE: `scale_*_stepsn` is a *continuous* binned scale, so `breaks` must be
# finite. Passing -Inf/Inf makes the open-ended end bins rescale to a
# non-finite value -> palette returns NA -> drawn as grey (na.value). Drop the
# infinite breaks here; the open-ended triangles are still drawn by
# `guide_coloursteps2()` (which always renders triangle ends), so no semantics
# are lost. Note the bin colours are *interpolated* along the gradient and thus
# only approximate `cols`; for exact per-level colours use the discrete `cut`
# path above (stat_levels + scale_color_manual).
ggplot(df, aes(x, y, color = x)) +
  geom_point() +
  scale_color_stepsn(
    colors = cols,
    breaks = brks[is.finite(brks)],
    guide = guide_coloursteps2(title = "lgd")
  ) +
  theme(
    legend.title = element_blank(),
    legend.margin = margin(l = -2)
  )


# example 3 
df <- expand.grid(X1 = 1:10, X2 = 1:10)
df$value <- df$X1 * df$X2

brks = c(10, 15, 25, 50)
nbrk <- length(brks) + 1
cols = get_color(rcolors$amwg256, nbrk)

# This can be changed with the `even.steps` argument
ggplot(df, aes(X1, X2)) +
  geom_tile(aes(fill = value)) +
  scale_fill_stepsn(
    colors = cols, breaks = brks,
    guide = guide_colorsteps2()
  ) +
  theme(
    legend.title = element_blank(),
    legend.margin = margin(l = -2)
  )