Text based boxplot

Description

Produces rudimentary ascii boxplots. The boxplot statistics are produced using the boxplot.stats function.

Usage

txtboxplot(..., range = 1.5, legend = NULL, xlab = NULL,
           width = round(options()$width * 0.8))

Arguments

Note

Due to rounding to a relatively crude grid results can only be approximate. E.g. the equally spaced axis ticks may be non-equally spaced in the plot.

Author(s)

Bjoern Bornkamp

See Also

txtplot

Examples

  rand1 <- rnorm(100, 1, 2)
  rand2 <- rnorm(50, 2, 2)
  rand3 <- rnorm(50, 2, 5)
  txtboxplot(rand1)
  txtboxplot(rand1, rand2, rand3)

Display a Text Image of a Matrix

Description

Print a rudimentary image of a matrix on the R console using a user-supplied alphabet as a palette of sorts.

Usage

txtimage(z, width, height, yaxis = c('up', 'down'), transpose = TRUE,
         legend = TRUE, na.char = ' ', alphabet = 0:9, Lanczos = 3)

Arguments

Details

By default, txtimage mimics the behaviour of image, drawing the rows of the matrix along the X axis and making the Y axis grow from bottom to the top of the plot. The function can be made to mimic matrix print instead (rows arranged vertically from top to bottom) by specifying yaxis and image.transpose arguments.

If requested width or height is different from dimensions of the matrix, it is resampled using the Lanczos filter for a given downsampling ratio r and window parameter a:

% L(x) = \mathrm{sinc}(x) \, \mathrm{sinc}(x/a) \, | x | < a

% S_{ij} = \sum_{k, l} s_{kl} % L \left( i - \frac{k}{r} \right) % L \left( j - \frac{l}{r} \right)

When resampling, the rows and columns are assumed to correspond to a uniform linear grid.

Value

The function is called for its side effect of printing the textual plot on the R console using cat, but it also invisibly returns the resulting character matrix. If legend is TRUE, the 'cuts' attribute contains the values separating the intervals used for characters in the alphabet (the copy of which is stored in the 'alphabet' attribute).

Note

Resampling constant signals may produce rounding errors that get greatly amplified after scaling them to diff(range(z)). For constant signals this is compensated by not allowing the resampling process to increase the range of the signal, but if the range of the matrix values is already really small (comparable to .Machine$double.eps, but not zero), the result of resampling process may not make sense.

Resampling high frequency signals (e.g. outer(1:200, 1:200, function(x,y) cos(x*y))) might give hard-to-interpret results.

Author(s)

Ivan Krylov

References

Szeliski, R. (2010) Computer Vision: Algorithms and Applications. Section 3.5.2: Decimation.

See Also

symnum, image

Examples

  txtimage(datasets::volcano)
  ## Not run: 
  ## try this if your terminal supports shade/block characters
  txtimage(datasets::volcano, alphabet = " \u2591\u2592\u2593\u2588")
  
## End(Not run)

Ascii graphics

Description

Provides a function to produce rudimentary ascii graphics directly in the terminal window.

txtplot provides the basic plotting function of two numeric vectors. All other functions below are based on this.
txtcurve is a text based equivalent of the curve function
txtdensity is a text based density estimation function based on the density function
txtacf is a text based equivalent of the acf function and based on the acf function.
txtbarchart is a text based barplot and plots the relative frequences of the occurences of the different levels of a factor (in percent)

Usage

txtplot(x, y = NULL, pch = "*", width = round(options()$width*0.8),
        height = round(0.25*width), xlab = NULL, ylab = NULL,
        xlim = NULL, ylim = NULL)

txtcurve(expr, from = NULL, to = NULL, n = 101,
         pch = "*", width = round(options()$width*0.8),
         height = round(0.25*width), xlab = NULL, ylab = NULL)

txtdensity(x, pch = "*", width = round(options()$width*0.8),
        height = round(0.25*width), xlab = NULL, ylab = NULL)

txtacf(x, pch = "*", lag.max = 20, type = c("correlation", "covariance", "partial"),
       na.action = na.fail, demean = TRUE, width = round(options()$width*0.8),
       height = round(0.25*width), xlab = NULL, ylab = NULL)

txtbarchart(x, pch = "*", width = round(options()$width*0.8),
            height = round(0.25*width), ylab = NULL)

Arguments

Note

Due to rounding to a relatively crude grid results can only be approximate! The equally spaced axis ticks, for example, may be non-equally spaced in the plot.

Due to the crude grid also there might be several points per pixel. The function uses the same plotting symbol no matter how many points coincide on one pixel

Author(s)

Bjoern Bornkamp

See Also

txtboxplot

Examples

  ## basic plotting function
  require(stats)
  txtplot(cars[,1], cars[,2])
  ## can include axis labels when desired
  txtplot(cars[,1], cars[,2], xlab = "speed", ylab = "distance")

  ## text based density plot
  txtdensity(rnorm(500))

  ## text based plotting of functions
  txtcurve(x/(x+1), 0, 4, xlab = "Emax model")

  ## text based acf
  txtacf(rnorm(100))

  ## text based barchart
  x <- factor(c("orange", "orange", "red", "green", "green", "red",
               "yellow", "purple", "purple", "orange"))
  txtbarchart(x)

  ## text based boxplots
  rand1 <- rnorm(100, 1, 2)
  rand2 <- rnorm(50, 2, 2)
  rand3 <- rnorm(50, 2, 5)
  txtboxplot(rand1)
  txtboxplot(rand1, rand2, rand3)