position_fill {ggplot2} | R Documentation

## Stack overlapping objects on top of one another.

### Description

`position_fill` additionally standardises each stack to have unit height.

### Usage

    position_fill()

    position_stack()

### See Also

See `geom_bar` and `geom_area` for more examples.

Other position adjustments: `position_dodge`, `position_identity`, `position_jitterdodge`, `position_jitter`, `position_nudge`

### Examples

    # Stacking is the default behaviour for most area plots:
    ggplot(mtcars, aes(factor(cyl), fill = factor(vs))) + geom_bar()
    # Fill makes it easier to compare proportions
    ggplot(mtcars, aes(factor(cyl), fill = factor(vs))) +
      geom_bar(position = "fill")

    # To change stacking order, use factor() to change order of levels
    mtcars$vs <- factor(mtcars$vs, levels = c(1,0))
    ggplot(mtcars, aes(factor(cyl), fill = factor(vs))) + geom_bar()

    ggplot(diamonds, aes(price, fill = cut)) +
      geom_histogram(binwidth = 500)
    # When used with a histogram, position_fill creates a conditional density
    # estimate
    ggplot(diamonds, aes(price, fill = cut)) +
      geom_histogram(binwidth = 500, position = "fill")

    # Stacking is also useful for time series
    data.set <- data.frame(
      Time = c(rep(1, 4),rep(2, 4), rep(3, 4), rep(4, 4)),
      Type = rep(c('a', 'b', 'c', 'd'), 4),
      Value = rpois(16, 10)
    )

    ggplot(data.set, aes(Time, Value)) + geom_area(aes(fill = Type))

    # If you want to stack lines, you need to say so:
    ggplot(data.set, aes(Time, Value)) + geom_line(aes(colour = Type))
    ggplot(data.set, aes(Time, Value)) +
      geom_line(position = "stack", aes(colour = Type))

    # But realise that this makes it *much* harder to compare individual
    # trends

[Package ggplot2 version 2.1.0 Index]