image270: Display a Color Image

In HenrikBengtsson/R.basic: [R] Class Library - Stand-alone basic functions [DEPRECATED]

Description

Creates a grid of colored or gray-scale rectangles with colors corresponding to the values in x. This can be used to display three-dimensional or spatial data aka images. This method is identical to image() except that it first rotates the image 270 degrees (equals 90 degrees clockwise) so that x[1,1] is in the upper left corner.

Usage

## Default S3 method:
image270(z, ...)

Arguments

z	a matrix containing the values to be plotted (NA's are allowed).
...	Any arguments that image() accepts.

Author(s)

Henrik Bengtsson

See Also

image.

Examples

   x <- y <- seq(-4 * pi, 4 * pi, len = 27)
   r <- sqrt(outer(x^2, y^2, "+"))
   z <- cos(r^2) * exp(-r/6)
   z[2,] <- min(z) # To show that z[1,1] is in the
   z[,2] <- max(z) # upper left corner.
 
   colorMap <- gray((0:32)/32)
   image270(z, col=colorMap)
   image270(t(z), col=colorMap)
   image270(mirror(z), col=colorMap)
   image270(flip(z), col=colorMap)
 
   img <- matrix("white", nrow=12, ncol=9)
   img[2:3,c(2:3,7:8)] <- "blue"
   img[5:6,5] <- "green"
   img[9,c(3,7)] <- "red"
   img[10,4:6] <- "red"
 
   z <- rgb2col(col2rgb(img))   # assert format "#rrggbb"
   colorMap <- sort(unique(z))
   z <- match(z, colorMap)      # color indices
   dim(z) <- dim(img)
 
   image270(z, col=colorMap)
   image270(rotate90(z), col=colorMap)
 

HenrikBengtsson/R.basic documentation built on May 6, 2019, 11:51 p.m.