plot_image {plotfunctions}

Add images to plots.

Description

Add images to plots.

Usage

plot_image(
  img,
  type = "image",
  col = NULL,
  show.axes = FALSE,
  xrange = c(0, 1),
  yrange = c(0, 1),
  keep.ratio = FALSE,
  adj = 0,
  fill.plotregion = FALSE,
  replace.colors = NULL,
  add = FALSE,
  interpolate = TRUE,
  ...
)

Arguments

img

Matrix or image object (list with 'image', a matrix, and 'col', a vector with color values), or a string indicating the filename of an image to read.

type

String, 'image' (default), 'png', 'jpeg', 'gif'

col

Vector with colors.

show.axes

Logical: whether or not to plot the axes.

xrange

Two-value vector providing the xleft and xright coordinate values of the picture. Default set to c(0,1).

yrange

Two-value vector providing the ybottom and ytop coordinate values of the picture. Default set to c(0,1).

keep.ratio

Logical: whether or not to keep the original picture ratio.

adj

Numeric value indicating the position of the shortest picture side with respect to xrange or yrange. Only applies when keep.ratio=TRUE. See examples.

fill.plotregion

Logical: whether or not to fill the complete plot region. Defaults to FALSE.

replace.colors

Named list for replacing colors. The names are the colors (in hexadecimal values), or regular expressions matching colors. The values are the replacements.

add

Logical: whether or not to add the plot to the current plot.

interpolate

Logical: a logical vector (or scalar) indicating whether to apply linear interpolation to the image when drawing.

...

Other arguments for plotting, see par.

Value

Optionally returns

Author(s)

Jacolien van Rij

See Also

Other Functions for plotting: addInterval(), add_bars(), add_n_points(), alphaPalette(), alpha(), check_normaldist(), color_contour(), dotplot_error(), drawDevArrows(), emptyPlot(), errorBars(), fill_area(), getCoords(), getFigCoords(), getProps(), gradientLegend(), legend_margin(), marginDensityPlot(), plot_error(), plotsurface(), sortBoxplot()

Examples

# see Volcano example at help(image)
# create image object:
myimg <- list(image=volcano-min(volcano), col=terrain.colors(max(volcano)-min(volcano)))
# create emoty plot window:
emptyPlot(1,1, main='Volcano images')
# add image topleft corner:
plot_image(img=myimg, xrange=c(0,.25), yrange=c(.75,1), add=TRUE)
# add transparent image as overlay:
myimg$col <- alpha(myimg$col, f=.25)
plot_image(img=myimg, add=TRUE, fill.plotregion=TRUE, bty='n')
# add image:
myimg$col <- topo.colors(max(myimg$image))
plot_image(img=myimg, xrange=c(0.125,.375), yrange=c(.5,.875), add=TRUE)
# add some points and lines:
points(runif(10,0,1), runif(10,0,1), type='o')

# keep ratio:
emptyPlot(1,1, main='Volcano images')
# I would like to add an image in the following field:
rect(xleft=0, xright=.5, ybottom=0, ytop=.3, col='gray', border=NA)
# add image with keep.ratio=true
plot_image(img=myimg, xrange=c(0,.5), yrange=c(0,.3), 
    add=TRUE, keep.ratio=TRUE, border=NA)
# as y-side is longest, this side will be fitted in 
# the rectangle and the x position adjusted with adj:
plot_image(img=myimg, xrange=c(0,.5), yrange=c(0,.3), 
    add=TRUE, keep.ratio=TRUE, border=2, adj=0.5)
plot_image(img=myimg, xrange=c(0,.5), yrange=c(0,.3), 
    add=TRUE, keep.ratio=TRUE, border=3, adj=1)

# keep.ratio and border:
plot_image(img=myimg, xrange=c(0,1), yrange=c(0,1), 
    keep.ratio=TRUE, adj=0.5)
plot_image(img=myimg, xrange=c(0,.5), yrange=c(0,1), 
    keep.ratio=TRUE, adj=0.5)
emptyPlot(1,1, axes=FALSE)
plot_image(img=myimg, xrange=c(0,1), yrange=c(0,1), 
    add=TRUE, keep.ratio=TRUE, adj=0.5)