ggimage function

Plot an image using ggplot2

ggimage is the near ggplot2 equivalent of image.

ggimage(mat, fullpage = TRUE, coord_equal = TRUE, scale_axes = FALSE)

Arguments

• mat: a matrix, imagematrix, array, or raster (something that can be coerced by as.raster)
• fullpage: should the image take up the entire viewport?
• coord_equal: should the axes units be equal?
• scale_axes: should the axes be (0,ncol(mat)-1)x(0,nrow(mat)-1) (F) or (0,1)x(0,1) (T)

Returns

a ggplot object

Examples

img <- matrix(1:16, 4, 4)
image(img)
ggimage(t(img[,4:1]), fullpage = FALSE, scale_axes = TRUE)
ggimage(t(img[,4:1]), fullpage = FALSE)

## Not run:

# not run due to slow performance

data(hadley)
ggimage(hadley)
ggimage(hadley, coord_equal = FALSE)

x <- seq(1, 438, 15); n <- length(x)
df <- data.frame(x = x, y = -(120*(scale((x - 219)^3 - 25000*x) + rnorm(n)/2 - 3)))
qplot(x, y, data = df, geom = c('smooth','point'))
ggimage(hadley, fullpage = FALSE) +
  geom_smooth(
    aes(x = x, y = y),
    data = df, color = 'green', size = 1
  ) +
  geom_point(
    aes(x = x, y = y),
    data = df, color = 'green', size = 3
  )
## End(Not run)

Author(s)

David Kahle david@kahle.io