plot.matrix: plot.matrix

In plot.matrix: Visualizes a Matrix as Heatmap

plot.matrix

Description

Visualizes a matrix with a colored heatmap and optionally a color key. It distinguishes between numeric and non-numeric matrices. You may need to modify mar with the graphics::par() command from its default c(5.1,4.1,4.1,2.1). For further see the vignette vignette('plot.matrix')

Usage

## S3 method for class 'matrix'
plot(
  x,
  y = NULL,
  breaks = NULL,
  col = heat.colors,
  na.col = "white",
  na.cell = TRUE,
  na.print = TRUE,
  digits = NA,
  fmt.cell = NULL,
  fmt.key = NULL,
  spacing.key = c(1, 0.5, 0),
  polygon.cell = NULL,
  polygon.key = NULL,
  text.cell = NULL,
  key = list(side = 4, las = 1),
  axis.col = list(side = 1),
  axis.row = list(side = 2),
  axis.key = NULL,
  max.col = 70,
  ...
)

Arguments

x	matrix
y	unused
breaks	breaks for numeric values or values for col
col	a vector of colors or a function, e.g. grDevices::heat.colors()] with one parameter n
na.col	color for missing value (default: white)
na.cell	to draw cells with missing values (default: TRUE)
na.print	print NA (or any given characters) when values are missing. If FALSE, nothing is printed. If na.cell is FALSE, this will have no effect.
digits	number of digits for numeric data or length of string for non-numeric data
fmt.cell	format string for writing matrix entries, overwrites digits, defaults to NULL
fmt.key	format string for writing key entries, overwrites digits, defaults to fmt
spacing.key	spacing between plot and legend, key width, spacing between key and axis (default: c(1,0.5,0))
polygon.cell	list of parameters used for graphics::polygon() for heatmap
polygon.key	list of parameters used for graphics::polygon() for key
text.cell	list of parameters used for graphics::text() for matrix entries
key	list of parameters used for [graphics::axis(). If set to NULL then no information will be plotted. Instead of key=list(side=4) you may use key=4 or key="right".
axis.col	list of parameters used for graphics::axis() for axis of matrix columns. Instead of axis.col=list(side=1) you may use axis.col=1 or axis.col="bottom".
axis.row	list of parameters used for graphics::axis() for axis of matrix rows. Instead of axis.row=list(side=2) you may use axis.row=2 or axis.col="left".
axis.key	as key
max.col	numeric: if the distance between the text color and the cell color is smaller then max.col then either white or black will be used as text color, defaults to 70
...	further parameter given to the graphics::plot() command

Details

A color key is drawn if either key (defaults to list(cex=1)) or fmt.key (defaults to NULL) is not NULL.

If you want to plot the matrix entries you must set either digits or fmt. For a non-numeric matrix digits gives the length of the string printed, a negative value results in right-justified string. For a numeric matrix digits determines the number of decimal places, a negative value uses a "exponential" decimal notation. You may set format strings fmt and fmt.key directly. Settings digits leads to the following format strings (n the absolute value of digits):

x numeric and digits>0:	"%+.nf"
x numeric and digits<0:	"%+.ne"
x non-numeric and digits>0:	"%+ns"
x non-numeric and digits<0:	"%-ns"

If no colors are given then the grDevices::heat.colors() will be used. Alternatively you may specify your own color function that delivers a vector with n colors if called by col(n). The final colors and breaks used depend if plot.matrix gets a numeric or non-numeric matrix.

Numeric matrix: In general it must hold length(col)+1==length(breaks).

1. breaks==NULL and col==NULL

The colors are taken from heat.colors(10) and the eleven breaks are calculated as an equidistant grid between min(x) and max(x).

2. breaks==NULL and col is a color function

Ten colors are taken from the color function and eleven breaks are calculated as an equidistant grid between min(x) and max(x).

3. breaks==NULL and col is a vector of colors

The length(col)+1 breaks are calculated as an equidistant grid between min(x) and max(x).

4. breaks are given and col==NULL

The colors are taken from heat.colors(length(breaks)-1).

5. breaks are given and col is a color function

The length(breaks)-1 colors are taken from the color function.

6. breaks are given and col is a vector of colors

If not length(col)+1==length(breaks) holds then the length(col)+1 breaks are calculated as an equidistant grid between min(breaks) and max(breaks).

Non-numeric matrix: In general it must hold length(col)==length(breaks). At first the number of unique elements in x is determined: nu.

1. breaks==NULL and col==NULL

The colors are taken from heat.colors(nu) and the breaks are set to the unique elements of x.

2. breaks==NULL and col is a color function

The nu colors are taken from color function and the breaks are set to the unique elements of x.

3. breaks==NULL and col is a vector of colors

The length(col) breaks are calculated as an equidistant grid between min(x) and max(x).

4. breaks are given and color==NULL

The colors are taken from heat.colors(length(breaks)).

5. breaks are given and color is a color function

The length(breaks) colors are taken from color function.

6. breaks are given and color is a vector of colors

If not length(colors)==length(breaks) holds then either breaks or color is shorten to the shorter of both.

If the difference between polygon color and the text color is smaller max.col then as text color is either white or black (depending which one is further away from the polygon color). The distance is computed as Δ C/3 as in https://en.wikipedia.org/wiki/Color_difference#Euclidean given.

Value

invisibly a list with elements

cell.polygon[[i,j]]

the polygon parameters used to draw the elements of the matrix

cell.text[[i,j]]

the text parameters used to draw the elements of the matrix

plot

the plot parameters used to draw the basic plot

axis.col

the axis parameters used to draw column axis

axis.row

the axis parameters used to draw row axis

key.polygon[[i]]

the polygon parameters used to draw the elements of the key

key.axis

the axis parameters used to draw key axis

A NULL means the elements has not been drawn.

Note

The use of fmt or fmt.key have the same restrictions as the use of fmt in base::sprintf():

The format string is passed down the OS's sprintf function, and incorrect formats can cause the latter to crash the R process. R does perform sanity checks on the format, but not all possible user errors on all platforms have been tested, and some might be terminal.

Examples

par(mar=c(5.1, 4.1, 4.1, 4.1))
# numeric matrix
x <- matrix(runif(50), nrow=10)
plot(x)
plot(x, key=NULL)
plot(x, key=list(cex.axis=0.5, tick=FALSE))
plot(x, digits=3)
plot(x, breaks=range(x), digits=3, cex=0.6)
# logical matrix
m <- matrix(runif(50)<0.5, nrow=10)
plot(m)
plot(m, col=c("red", "blue"))
plot(m, key=NULL, digits=1)
# character matrix
s <- matrix(sample(letters[1:10], 50, replace=TRUE), nrow=10)
plot(s)
plot(s, col=topo.colors)
plot(s, digits=10)
plot(s, digits=1, col=heat.colors(5), breaks=letters[1:5])
plot(s, digits=1, col=heat.colors(5), breaks=c('a', 'c', 'e', 'g', 'i'))
# contingency table
tab <- table(round(rnorm(100)), round(rnorm(100)))
plot(unclass(tab))
# chisquare test residuals
cst <- chisq.test(apply(HairEyeColor, 1:2, sum))
col <- colorRampPalette(c("blue", "white", "red"))
plot(cst$residuals, col=col, breaks=c(-7.5,7.5))
# triangular matrix
x[upper.tri(x)] <- NA
plot(x, digit=2)
plot(x, na.print=FALSE)
plot(x, na.cell=FALSE)
# use the standard plot instead of plot.matrix
x <- matrix(runif(50), nrow=2)
plot(as.data.frame(x))
plot.default(x)
## Not run: 
# unload the package permanently with devtools
library("devtools")
unload('plot.matrix')

## End(Not run)

plot.matrix documentation built on March 18, 2022, 6:19 p.m.