Package 'labeling'

Title: Axis Labeling
Description: Functions which provide a range of axis labeling algorithms.
Authors: Justin Talbot,
Maintainer: Nuno Sempere <[email protected]>
License: MIT + file LICENSE | Unlimited
Version: 0.4.3
Built: 2024-05-12 08:15:51 UTC
Source: CRAN

Help Index

Axis labeling

Description

Functions for positioning tick labels on axes

Details

Package: labeling
Type: Package
Version: 0.4.3
Date: 2023-08-29
License: Unlimited
LazyLoad: yes

Implements a number of axis labeling schemes, including those compared in An Extension of Wilkinson's Algorithm for Positioning Tick Labels on Axes by Talbot, Lin, and Hanrahan, InfoVis 2010.

Author(s)

Justin Talbot [email protected]

References

Heckbert, P. S. (1990) Nice numbers for graph labels, Graphics Gems I, Academic Press Professional, Inc. Wilkinson, L. (2005) The Grammar of Graphics, Springer-Verlag New York, Inc. Talbot, J., Lin, S., Hanrahan, P. (2010) An Extension of Wilkinson's Algorithm for Positioning Tick Labels on Axes, InfoVis 2010.

See Also

extended, wilkinson, heckbert, rpretty, gnuplot, matplotlib, nelder, sparks, thayer, pretty

Examples

heckbert(8.1, 14.1, 4)	# 5 10 15
wilkinson(8.1, 14.1, 4)	# 8 9 10 11 12 13 14 15
extended(8.1, 14.1, 4)	# 8 10 12 14
# When plotting, extend the plot range to include the labeling
# Should probably have a helper function to make this easier
data(iris)
x <- iris$Sepal.Width
y <- iris$Sepal.Length
xl <- extended(min(x), max(x), 6)
yl <- extended(min(y), max(y), 6)
plot(x, y,
    xlim=c(min(x,xl),max(x,xl)),
    ylim=c(min(y,yl),max(y,yl)),
    axes=FALSE, main="Extended labeling")
axis(1, at=xl)
axis(2, at=yl)

An Extension of Wilkinson's Algorithm for Position Tick Labels on Axes

Description

extended is an enhanced version of Wilkinson's optimization-based axis labeling approach. It is described in detail in our paper. See the references.

Usage

extended(dmin, dmax, m, Q = c(1, 5, 2, 2.5, 4, 3),
    only.loose = FALSE, w = c(0.25, 0.2, 0.5, 0.05))

Arguments

dmin

minimum of the data range
dmax

maximum of the data range
m

number of axis labels
Q

set of nice numbers
only.loose

if true, the extreme labels will be outside the data range
w

weights applied to the four optimization components (simplicity, coverage, density, and legibility)

Value

vector of axis label locations

Author(s)

Justin Talbot [email protected]

References

Talbot, J., Lin, S., Hanrahan, P. (2010) An Extension of Wilkinson's Algorithm for Positioning Tick Labels on Axes, InfoVis 2010.

Generate figures from An Extension of Wilkinson's Algorithm for Position Tick Labels on Axes

Description

Generates Figures 2 and 3 from our paper.

Usage

extended.figures(samples = 100)

Arguments

samples

number of samples to use (in the paper we used 10000, but that takes awhile to run).

Value

produces plots as a side effect

Author(s)

Justin Talbot [email protected]

References

Talbot, J., Lin, S., Hanrahan, P. (2010) An Extension of Wilkinson's Algorithm for Positioning Tick Labels on Axes, InfoVis 2010.

gnuplot's labeling algorithm

Description

gnuplot's labeling algorithm

Usage

gnuplot(dmin, dmax, m)

Arguments

dmin

minimum of the data range
dmax

maximum of the data range
m

number of axis labels

Value

vector of axis label locations

Author(s)

Justin Talbot [email protected]

References

http://www.gnuplot.info/

Heckbert's labeling algorithm

Description

Heckbert's labeling algorithm

Usage

heckbert(dmin, dmax, m)

Arguments

dmin

minimum of the data range
dmax

maximum of the data range
m

number of axis labels

Value

vector of axis label locations

Author(s)

Justin Talbot [email protected]

References

Heckbert, P. S. (1990) Nice numbers for graph labels, Graphics Gems I, Academic Press Professional, Inc.

Matplotlib's labeling algorithm

Description

Matplotlib's labeling algorithm

Usage

matplotlib(dmin, dmax, m)

Arguments

dmin

minimum of the data range
dmax

maximum of the data range
m

number of axis labels

Value

vector of axis label locations

Author(s)

Justin Talbot [email protected]

References

https://matplotlib.org/

Nelder's labeling algorithm

Description

Nelder's labeling algorithm

Usage

nelder(dmin, dmax, m,
    Q = c(1, 1.2, 1.6, 2, 2.5, 3, 4, 5, 6, 8, 10))

Arguments

dmin

minimum of the data range
dmax

maximum of the data range
m

number of axis labels
Q

set of nice numbers

Value

vector of axis label locations

Author(s)

Justin Talbot [email protected]

References

Nelder, J. A. (1976) AS 96. A Simple Algorithm for Scaling Graphs, Journal of the Royal Statistical Society. Series C., pp. 94-96.

R's pretty algorithm implemented in R

Description

R's pretty algorithm implemented in R

Usage

rpretty(dmin, dmax, m = 6, n = floor(m) - 1,
    min.n = n%/%3, shrink.sml = 0.75, high.u.bias = 1.5,
    u5.bias = 0.5 + 1.5 * high.u.bias)

Arguments

dmin

minimum of the data range
dmax

maximum of the data range
m

number of axis labels
n

number of axis intervals (specify one of m or n)
min.n

nonnegative integer giving the minimal number of intervals. If min.n == 0, pretty(.) may return a single value.
shrink.sml

positive numeric by a which a default scale is shrunk in the case when range(x) is very small (usually 0).
high.u.bias

non-negative numeric, typically > 1. The interval unit is determined as {1,2,5,10} times b, a power of 10. Larger high.u.bias values favor larger units.
u5.bias

non-negative numeric multiplier favoring factor 5 over 2. Default and 'optimal': u5.bias = .5 + 1.5*high.u.bias.

Value

vector of axis label locations

Author(s)

Justin Talbot [email protected]

References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

Sparks' labeling algorithm

Description

Sparks' labeling algorithm

Usage

sparks(dmin, dmax, m)

Arguments

dmin

minimum of the data range
dmax

maximum of the data range
m

number of axis labels

Value

vector of axis label locations

Author(s)

Justin Talbot [email protected]

References

Sparks, D. N. (1971) AS 44. Scatter Diagram Plotting, Journal of the Royal Statistical Society. Series C., pp. 327-331.

Thayer and Storer's labeling algorithm

Description

Thayer and Storer's labeling algorithm

Usage

thayer(dmin, dmax, m)

Arguments

dmin

minimum of the data range
dmax

maximum of the data range
m

number of axis labels

Value

vector of axis label locations

Author(s)

Justin Talbot [email protected]

References

Thayer, R. P. and Storer, R. F. (1969) AS 21. Scale Selection for Computer Plots, Journal of the Royal Statistical Society. Series C., pp. 206-208.

Wilkinson's labeling algorithm

Description

Wilkinson's labeling algorithm

Usage

wilkinson(dmin, dmax, m,
    Q = c(1, 5, 2, 2.5, 3, 4, 1.5, 7, 6, 8, 9),
    mincoverage = 0.8,
    mrange = max(floor(m/2), 2):ceiling(6 * m))

Arguments

dmin

minimum of the data range
dmax

maximum of the data range
m

number of axis labels
Q

set of nice numbers
mincoverage

minimum ratio between the the data range and the labeling range, controlling the whitespace around the labeling (default = 0.8)
mrange

range of m, the number of tick marks, that should be considered in the optimization search

Value

vector of axis label locations

Note

Ported from Wilkinson's Java implementation with some changes. Changes: 1) m (the target number of ticks) is hard coded in Wilkinson's implementation as 5. Here we allow it to vary as a parameter. Since m is fixed, Wilkinson only searches over a fixed range 4-13 of possible resulting ticks. We broadened the search range to max(floor(m/2),2) to ceiling(6*m), which is a larger range than Wilkinson considers for 5 and allows us to vary m, including using non-integer values of m. 2) Wilkinson's implementation assumes that the scores are non-negative. But, his revised granularity function can be extremely negative. We tweaked the code to allow negative scores. We found that this produced better labelings. 3) We added 10 to Q. This seemed to be necessary to get steps of size 1. It is possible for this algorithm to find no solution. In Wilkinson's implementation, instead of failing, he returns the non-nice labels spaced evenly from min to max. We want to detect this case, so we return NULL. If this happens, the search range, mrange, needs to be increased.

Author(s)

Justin Talbot [email protected]

References

Wilkinson, L. (2005) The Grammar of Graphics, Springer-Verlag New York, Inc.