R: Methods for Adding a Pixmap Logo to a Plot

addlogo-methods {pixmap} | R Documentation

## Methods for Adding a Pixmap Logo to a Plot

### Description

This method allows the addition of a re-scaled pixmap to an existing plot, possibly as a logo, optionally preserving aspect. It may be used interactively with `locator`, and is positioned in the coordinate system of the plot region. Since the logo is displayed using `image`, it does not yet seem possible to use the function outside this region.

### Usage

      addlogo(x, ...)
      ## S4 method for signature 'pixmap'
    addlogo(x, px, py, asp = NULL)

### Arguments

`x` | an object of class `pixmap`
`px` | a vector of two x coordinates, or a list with two named elements x and y, such as that returned by `locator`.
`py` | if px is not a list, a vector of two y coordinates
`asp` | if omitted or NULL (default), output respects both y coordinates, if a number greater than zero, aspect is preserved in proportion to the difference between x coordinates, multiplied by asp, and only the first y coordinate is respected.
`...` | potentially further arguments passed to and from methods.

### Value

The same pixmap object with changed bounding box and cell resolution

### Author(s)

Roger Bivand

### Examples

    x <- read.pnm(system.file("pictures/logo.ppm", package="pixmap")[1])
    plot(x)
    for (i in 1:7)
      addlogo(x, px=c(0, (101/77)*11), py=c((i-1)*11, i*11), asp=1)

[Package pixmap version 0.4-11 Index]