| mosaicplot {graphics} | R Documentation |
Plots a mosaic on the current graphics device.
mosaicplot(x, ...)
## Default S3 method:
mosaicplot(x, main = deparse(substitute(x)),
sub = NULL, xlab = NULL, ylab = NULL,
sort = NULL, off = NULL, dir = NULL,
color = NULL, shade = FALSE, margin = NULL,
cex.axis = 0.66, las = par("las"),
type = c("pearson", "deviance", "FT"), ...)
## S3 method for class 'formula':
mosaicplot(formula, data = NULL, ...,
main = deparse(substitute(data)), subset,
na.action = stats::na.omit)
x |
a contingency table in array form, with optional category
labels specified in the dimnames(x) attribute. The table is
best created by the table() command. |
main |
character string for the mosaic title. |
sub |
character string for the mosaic sub-title (at bottom). |
xlab,ylab |
x- and y-axis labels used for the plot; by default,
the first and second element of names(dimnames(X)) (i.e., the
name of the first and second variable in X). |
sort |
vector ordering of the variables, containing a permutation
of the integers 1:length(dim(x)) (the default). |
off |
vector of offsets to determine percentage spacing at each level of the mosaic (appropriate values are between 0 and 20, and the default is 20 times the number of splits for 2-dimensional tables, and 10 otherwise. Rescaled to maximally 50, and recycled if necessary. |
dir |
vector of split directions ("v" for vertical and
"h" for horizontal) for each level of the mosaic, one
direction for each dimension of the contingency table. The
default consists of alternating directions, beginning with a
vertical split. |
color |
logical or (recycling) vector of colors for color
shading, used only when shade is FALSE, or NULL
(default). By default, grey boxes are drawn. color=TRUE
uses a gamma-corrected grey palette. color=FALSE gives empty
boxes with no shading. |
shade |
a logical indicating whether to produce extended mosaic
plots, or a numeric vector of at most 5 distinct positive numbers
giving the absolute values of the cut points for the residuals. By
default, shade is FALSE, and simple mosaics are
created. Using shade = TRUE cuts absolute values at 2 and
4. |
margin |
a list of vectors with the marginal totals to be fit in
the log-linear model. By default, an independence model is fitted.
See loglin for further information. |
cex.axis |
The magnification to be used for axis annotation,
as a multiple of par("cex"). |
las |
numeric; the style of axis labels, see par. |
type |
a character string indicating the type of residual to be
represented. Must be one of "pearson" (giving components of
Pearson's chi-squared), "deviance" (giving
components of the likelihood ratio chi-squared), or
"FT" for the Freeman-Tukey residuals. The value of this
argument can be abbreviated. |
formula |
a formula, such as y ~ x. |
data |
a data frame (or list), or a contingency table from which
the variables in formula should be taken. |
... |
further arguments to be passed to or from methods. |
subset |
an optional vector specifying a subset of observations in the data frame to be used for plotting. |
na.action |
a function which indicates what should happen
when the data contains variables to be cross-tabulated, and these
variables contain NAs. The default is to omit cases which
have an NA in any variable. Since the tabulation will omit
all cases containing missing values, this will only be useful if the
na.action function replaces missing values. |
This is a generic function. It currently has a default method
(mosaicplot.default) and a formula interface
(mosaicplot.formula).
Extended mosaic displays visualize standardized residuals of a loglinear model for the table by color and outline of the mosaic's tiles. (Standardized residuals are often referred to a standard normal distribution.) Negative residuals are drawn in shaded of red and with broken outlines; positive ones are drawn in blue with solid outlines.
For the formula method, if data is an object inheriting from
classes "table" or "ftable", or an array with more than
2 dimensions, it is taken as a contingency table, and hence all
entries should be nonnegative. In this case, the left-hand side of
formula should be empty, and the variables on the right-hand
side should be taken from the names of the dimnames attribute of the
contingency table. A marginal table of these variables is computed,
and a mosaic of this table is produced.
Otherwise, data should be a data frame or matrix, list or
environment containing the variables to be cross-tabulated. In this
case, after possibly selecting a subset of the data as specified by
the subset argument, a contingency table is computed from the
variables given in formula, and a mosaic is produced from
this.
See Emerson (1998) for more information and a case study with television viewer data from Nielsen Media Research.
Missing values are not supported except via an na.action
function when data contains variables to be cross-tabulated.
A more flexible and extensible implementation of mosaic plots written
in the grid graphics system is provided in the function
mosaic in the contributed package vcd (Meyer,
Zeileis and Hornik, 2005).
S-PLUS original by John Emerson emerson@stat.yale.edu. Originally modified and enhanced for R by Kurt Hornik.
Hartigan, J.A., and Kleiner, B. (1984) A mosaic of television ratings. The American Statistician, 38, 32–35.
Emerson, J. W. (1998) Mosaic displays in S-PLUS: A general implementation and a case study. Statistical Computing and Graphics Newsletter (ASA), 9, 1, 17–23.
Friendly, M. (1994) Mosaic displays for multi-way contingency tables. Journal of the American Statistical Association, 89, 190–200.
Meyer, D., Zeileis, A., and Hornik, K. (2005) The strucplot framework: Visualizing multi-way contingency tables with vcd. Report 22, Department of Statistics and Mathematics, Wirtschaftsuniversität Wien, Research Report Series. http://epub.wu-wien.ac.at/dyn/openURL?id=oai:epub.wu-wien.ac.at:epub-wu-01_8a1
The home page of Michael Friendly (http://www.math.yorku.ca/SCS/friendly.html) provides information on various aspects of graphical methods for analyzing categorical data, including mosaic plots.
mosaicplot(Titanic, main = "Survival on the Titanic", color = TRUE) ## Formula interface for tabulated data: mosaicplot(~ Sex + Age + Survived, data = Titanic, color = TRUE) mosaicplot(HairEyeColor, shade = TRUE) ## Independence model of hair and eye color and sex. Indicates that ## there are more blue eyed blonde females than expected in the case ## of independence and too few brown eyed blonde females. ## The corresponding model is: fm <- loglin(HairEyeColor, list(1, 2, 3)) pchisq(fm$pearson, fm$df, lower.tail = FALSE) mosaicplot(HairEyeColor, shade = TRUE, margin = list(1:2, 3)) ## Model of joint independence of sex from hair and eye color. Males ## are underrepresented among people with brown hair and eyes, and are ## overrepresented among people with brown hair and blue eyes. ## The corresponding model is: fm <- loglin(HairEyeColor, list(1:2, 3)) pchisq(fm$pearson, fm$df, lower.tail = FALSE) ## Formula interface for raw data: visualize crosstabulation of numbers ## of gears and carburettors in Motor Trend car data. mosaicplot(~ gear + carb, data = mtcars, color = TRUE, las = 1) # color recycling mosaicplot(~ gear + carb, data = mtcars, color = 2:3, las = 1)