R: HCL-Based Continuous Sequential Color Scales for ggplot2

scale_colour_continuous_sequential {colorspace} | R Documentation

## HCL-Based Continuous Sequential Color Scales for ggplot2

### Description

Continuous ggplot2 color scales using the color palettes generated by `sequential_hcl`.

### Usage

    scale_colour_continuous_sequential(
      palette = NULL,
      c1 = NULL,
      c2 = NULL,
      cmax = NULL,
      l1 = NULL,
      l2 = NULL,
      h1 = NULL,
      h2 = NULL,
      p1 = NULL,
      p2 = NULL,
      alpha = 1,
      rev = TRUE,
      begin = 0,
      end = 1,
      na.value = "grey50",
      guide = "colourbar",
      aesthetics = "colour",
      n_interp = 11,
      ...
    )

    scale_color_continuous_sequential(
      palette = NULL,
      c1 = NULL,
      c2 = NULL,
      cmax = NULL,
      l1 = NULL,
      l2 = NULL,
      h1 = NULL,
      h2 = NULL,
      p1 = NULL,
      p2 = NULL,
      alpha = 1,
      rev = TRUE,
      begin = 0,
      end = 1,
      na.value = "grey50",
      guide = "colourbar",
      aesthetics = "colour",
      n_interp = 11,
      ...
    )

    scale_fill_continuous_sequential(..., aesthetics = "fill")

### Arguments

`palette` | The name of the palette to be used. Run `hcl_palettes(type = "sequential")` for available options.
`c1` | Beginning chroma value.
`c2` | Ending chroma value.
`cmax` | Maximum chroma value.
`l1` | Beginning luminance value.
`l2` | Ending luminance value.
`h1` | Beginning hue value.
`h2` | Ending hue value. If set to `NA`, generates a single-hue scale.
`p1` | Control parameter determining how chroma should vary (1 = linear, 2 = quadratic, etc.).
`p2` | Control parameter determining how luminance should vary (1 = linear, 2 = quadratic, etc.).
`alpha` | Numeric vector of values in the range `[0, 1]` for alpha transparency channel (0 means transparent and 1 means opaque).
`rev` | If `TRUE` (default), reverses the order of the colors in the color scale (compared to `sequential_hcl`).
`begin` | Number in the range of `[0, 1]` indicating to which point in the color scale the smallest data value should be mapped.
`end` | Number in the range of `[0, 1]` indicating to which point in the color scale the largest data value should be mapped.
`na.value` | Color to be used for missing data points.
`guide` | Type of legend. Use `"colourbar"` for continuous color bar.
`aesthetics` | The ggplot2 aesthetics to which this scale should be applied.
`n_interp` | Number of discrete colors that should be used to interpolate the continuous color scale. 11 will work fine in most cases.
`...` | common continuous scale parameters: 'name', 'breaks', 'labels', and 'limits'. See `continuous_scale` for more details.

### Details

If both a valid palette name and palette parameters are provided then the provided palette parameters overwrite the parameters in the named palette. This enables easy customization of named palettes.

Compared to `sequential_hcl` the ordering of the colors in the sequential ggplot2 scale are reversed by default (i.e., `rev = TRUE`) to be more consistent with ggplot2's own scales such as `scale_color_brewer`. For most named palettes this leads to darker and more colorful colors for larger values on the scale. This is typically the better default on light/white backgrounds.

### Examples

    library("ggplot2")

    # base plot
    gg <- ggplot(iris, aes(x = Species, y = Sepal.Width, color = Sepal.Length)) +
      geom_jitter(width = 0.3) + theme_minimal()

    # default settings
    gg + scale_color_continuous_sequential()

    # switch palette and overwrite some default values
    gg + scale_color_continuous_sequential(palette = "Reds", l1 = 20, c2 = 70, p1 = 1)

    # select a range out of the entire palette
    gg + scale_color_continuous_sequential(palette = "Heat", begin = 0.2, end = 0.8)

    # volcano plot
    df <- data.frame(height = c(volcano), x = c(row(volcano)), y = c(col(volcano)))
    ggplot(df, aes(x, y, fill = height)) +
      geom_raster() + scale_fill_continuous_sequential(palette = "Terrain", rev = FALSE) +
      coord_fixed(expand = FALSE)

[Package colorspace version 2.0-1 Index]