Description Usage Arguments Details Value Examples

View source: R/colour-mapping.r

Conveniently maps data values (numeric or factor/character) to colours according to a given palette, which can be provided in a variety of formats.

1 2 3 4 5 6 7 8 9 10 | ```
col_numeric(palette, domain, na.color = "#808080")
col_bin(palette, domain, bins = 7, pretty = TRUE,
na.color = "#808080")
col_quantile(palette, domain, n = 4, probs = seq(0, 1, length.out = n +
1), na.color = "#808080")
col_factor(palette, domain, levels = NULL, ordered = FALSE,
na.color = "#808080")
``` |

`palette` |
The colours or colour function that values will be mapped to |

`domain` |
The possible values that can be mapped. For If |

`na.color` |
The colour to return for |

`bins` |
Either a numeric vector of two or more unique cut points or a single number (greater than or equal to 2) giving the number of intervals into which the domain values are to be cut. |

`pretty` |
Whether to use the function |

`n` |
Number of equal-size quantiles desired. For more precise control,
use the |

`probs` |
See |

`levels` |
An alternate way of specifying levels; if specified, domain is ignored |

`ordered` |
If |

`col_numeric`

is a simple linear mapping from continuous numeric data
to an interpolated palette.

`col_bin`

also maps continuous numeric data, but performs
binning based on value (see the `base::cut()`

function).

`col_quantile`

similarly bins numeric data, but via the
`stats::quantile()`

function.

`col_factor`

maps factors to colours. If the palette is
discrete and has a different number of colours than the number of factors,
interpolation is used.

The `palette`

argument can be any of the following:

A character vector of RGB or named colours. Examples:

`palette()`

,`c("#000000", "#0000FF", "#FFFFFF")`

,`topo.colors(10)`

The name of an RColorBrewer palette, e.g.

`"BuPu"`

or`"Greens"`

.A function that receives a single value between 0 and 1 and returns a colour. Examples:

`colorRamp(c("#000000", "#FFFFFF"), interpolate="spline")`

.

A function that takes a single parameter `x`

; when called with a
vector of numbers (except for `col_factor`

, which expects
factors/characters), #RRGGBB colour strings are returned.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | ```
pal <- col_bin("Greens", domain = 0:100)
show_col(pal(sort(runif(10, 60, 100))))
# Exponential distribution, mapped continuously
show_col(col_numeric("Blues", domain = NULL)(sort(rexp(16))))
# Exponential distribution, mapped by interval
show_col(col_bin("Blues", domain = NULL, bins = 4)(sort(rexp(16))))
# Exponential distribution, mapped by quantile
show_col(col_quantile("Blues", domain = NULL)(sort(rexp(16))))
# Categorical data; by default, the values being coloured span the gamut...
show_col(col_factor("RdYlBu", domain = NULL)(LETTERS[1:5]))
# ...unless the data is a factor, without droplevels...
show_col(col_factor("RdYlBu", domain = NULL)(factor(LETTERS[1:5], levels=LETTERS)))
# ...or the domain is stated explicitly.
show_col(col_factor("RdYlBu", levels = LETTERS)(LETTERS[1:5]))
``` |

```
```

scales documentation built on Aug. 10, 2018, 1:17 a.m.

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