This vignette explains the unikn functions for plotting graphical elements and text decorations. (See the vignette on colors for general information on colors, color palettes, and corresponding functions, or the more specialized vignettes on color recipes and institutional colors.)
Please install and/or load the unikn package to get started:
Beyond providing support for colors, unikn provides functions for plotting graphical elements (like boxes) and text decorations (with colored backgrounds or underlining). Before illustrating these functions, please note some caveats:
Plotting text (i.e., graphically rendering characters) is rarely a good idea. In contrast to the vector fonts used by DTP programs, plotted text typically does not scale (when changing the size of images) and cannot be recognized automatically (e.g., copied, indexed, or scraped). Hence, the following functions should only be used when no better solutions are available (e.g., for adding text to graphs, or for obstructing automatic text recognition).
Like all other templates, our renderings are subject to constraints and limitations. For instance, as any standard installation of R lacks the prescribed “Theinhardt” fonts, we only mimic the official design specifications (in Arial, sans serif).
That said, digital decorations can be useful to emphasize or structure information, provided that they can be produced easily and flexibly. The unikn package helps preventing common mistakes by novices (e.g., boxes or lines extending beyond text, or step-functions in multi-line headings) and can be customized and improved by expert users. Hence, we hope that the following functions are useful for plotting graphical elements (e.g., boxes, logos, etc.) and help you achieve a uniform look when styling presentations or visualizations.
Please load the unikn package to get started:
As the text functions of unikn add styled text to an existing plot, we must first create a plot to which we can add text. unikn provides 2 basic functions for creating new plots:
slideplots an empty canvass (a rectangular box or frame);
xboxplots a colored box with an X in its top right corner.
Here are both commands with their default settings:
slide() # plot default slide
xbox() # plot default xbox
Both functions accept additional arguments to customize their appearance.
The background and border colors of slides can be changed by setting their
slide(col = pal_seeblau[], border = Petrol, lwd = 5) # set colors of slide background and border
slide(col = pal_peach[], border = NA) # colored slide without a border
Similarly, the background color of xboxes can be changed by the
xbox(col = Pinky) # set background color of xbox
By default, both
xbox fill the entire plotting region (i.e., all margins are set to 0).
The width of a slide is set to 4/3 of its height (of 1). To change this default, use the
dim argument for specifying the slide’s x- and y-dimensions, respectively:
Note that changes in slide dimensions are invisible when viewing images interactively, as R automatically scales images to the size of the canvass. They mostly affect the relation between metrics when adding elements to an object.
Similarly, an xbox has the default dimensions of a unit square (i.e.,
dim = c(1, 1)). To change this default, use the
dim argument for specifying the xbox’s
The two strokes of the X (in the top right corner) are orthogonal when viewing the
xbox at the aspect ratio indicated by
dim (i.e., here: at a ratio of width x = 1 to height y = 2). When viewing the box at any different aspect ratio, the X appears to be distorted. Hence, viewing and printing plots at the desired aspect ratio helps when creating an xbox.
There are three main functions for plotting text with decorations:
mark()allows highlighting text with colored background boxes;
uline()allows underlining text with colored lines;
post()allows posting text in rectangular
In addition, there are 2 auxiliary functions:
headline()allows plotting headlines with colored background boxes;
url_unikn()allows formatting URLs the uni.kn way.
The following sections illustrate the functions and their main options in turn.
mark() function allows highlighting text by plotting it with colored background boxes (to provide the functionality of “Markieren”):
mark() assumes that we want to add highlighted text to an existing plot. The text labels to be added are provided (as a character vector) by the
labels argument, their coordinates as the corresponding
y arguments. Various text decorations (i.e., text and background colors, text sizes, and font types) can be set by specifying additional arguments (i.e.,
# Some pre-existing plot: n <- 20 set.seed(1) par(mar = c(0, 0, 0, 0)) plot(x = runif(n), y = runif(n), type = "p", pch = 16, cex = 20, col = grey(0, .2), axes = FALSE, xlab = "", ylab = "") # Add 1 marked label: mark(labels = "Some messy plot", x = .02, y = .9) # Add 2 more marked labels: mark(labels = c("Note something here.", "More highlighting here."), x = c(.1, .6), y = c(.2, .4), col_bg = c(pal_seeblau[], pal_peach[]), cex = 1.2)
If no pre-existing plot is available, setting the
new_plot argument to either
"slide" will generate a new default plot (by calling the
slide() function described above):
# A sentence to plot: s <- c("Markieren", "ist ein Bestandteil", "von Studieren.") # Create a new plot (of type "slide"): mark(labels = s, x = 0, y = .85, y_layout = .03, col_bg = Seeblau, cex = 1.5, new_plot = "slide") # Add text to the same plot: mark(labels = s, x = 0, y = .40, y_layout = .03, col_bg = pal_pinky[], cex = 1.5, new_plot = "none")
Rather than providing explicit
y coordinates for all text elements in
labels, the calls above defined an initial coordinate and used a numeric
y_layout argument to fix the distance between consecutive text labels (to a value of
As an alternative to numeric coordinates and position values,
y_layout also accept some special values (as character strings):
x_layout = "center"for centering labels horizontally (on the first label or the middle),
x_layout = "left"left-justifies labels (on the first label or the middle), and
x_layout = "right"right-justifies labels (on the first label or the middle).
y_layout = "even"for an even distribution of labels across the available y-space, and
y_layout = "flush"to omit space between adjacent labels (as in
y_layout = 0).
Thus, the position and orientation of the text labels can be controlled by using the
?mark for details.
uline() function allows emphasizing text by plotting it with colored underlining (to provide the functionality of “Unterstreichen”):
mark() above, the
uline() command distinguishes between creating a new plot (by setting
new_plot to either
"blank" or “
slide”) or adding to a pre-existing plot (by using the default
new_plot = "none"):
The arguments for text elements (
labels), text positions (
y_layout), and text properties and decorations (
font) work as they do for
mark(). For instance, shorter vectors are recycled to match the length of
The position and orientation of the text labels can be controlled by using the
post() function allows adding text to a rectangular
xbox (to provide the functionality of “Merken”):
post() assumes a pre-existing
xbox to which the text elements of
labels are to be added.
For square boxes, setting
"xbox" creates a new
xbox with its default dimensions of
dim = c(1, 1).
By adjusting its color and text arguments,
post() allows creating simple badges or logos:
Another potential use of
post() is for creating images providing contact details:
address <- c("Dr. B. F. Skinner", " ", "Department of Psychology", "Office F101", "Tel.: +49 7531 88-0815", "Fax: +49 7531 88-0810", "email@example.com") post(labels = "Contact", y = .7, cex = 1.2, font = 2, col_bg = Petrol, new_plot = "xbox") # create new plot post(labels = address, y = .5, y_layout = .03, new_plot = "none") # add to plot
As above, the position and orientation of the text labels can be controlled by using the
heading() function makes it easy to create recognizable headings:
By default, the function creates a new slide (i.e.,
new_plot = "slide") and positions the text elements of
labels on its left edge (i.e.,
x = 0,
y = .8 and
y_layout = "flush"). Headings violating the recommendations (see p. 25 of the CD manual) will generate a message, for instance:
When colors are left unspecified,
heading() selects colors that are appropriate for the number of elements in
labels (i.e., shades of
col_bg = "default"). However, default colors can be overwritten by setting the
One of the more obscure rules (on p. 31 of the CD manual) concerns the rendering of URLs, in which typical web patterns (like “http” or “www”) are to be omitted and replaced by a typographical dash (which is longer than a hyphen). The
url_unikn utility function allows formatting URLs the uni.kn way:
The following versions of unikn and corresponding resources are currently available:
|A. unikn (R package):||Release version||https://CRAN.R-project.org/package=unikn|
|B. Online documentation:||Release version||https://hneth.github.io/unikn/|
The following vignettes provide instructions and examples for using the unikn colors, color palettes, and functions:
|1.||Colors||Colors and color functions|
|2.||Color recipes||Recipes for color-related tasks|
|3.||Institutional colors||Creating color palettes for other institutions|
|4.||Text||Text boxes and decorations|