qrmtools (version 0.0-10)

matrix_plot: Graphical Tool for Visualizing Matrices

Description

Plot of a matrix.

Usage

matrix_plot(x, ylim = rev(c(0.5, nrow(x) + 0.5)),
            xlab = "Column", ylab = "Row",
            scales = list(alternating = c(1,1), tck = c(1,0),
                          x = list(at = pretty(1:ncol(x)), rot = 90),
                          y = list(at = pretty(1:nrow(x)))),
            at = NULL, colorkey = NULL, col = c("royalblue3", "white", "maroon3"),
            col.regions = NULL, ...)

Arguments

x

matrix-like object.

ylim

y-axis limits in reverse order (for the rows to appear 'top down').

xlab

x-axis label.

ylab

y-axis label.

scales

see levelplot(); if NULL, labels and ticks are omitted.

at

see levelplot(). If NULL, a useful default is computed based on the given values in x.

colorkey

see levelplot(). If NULL, a useful default is computed based on at.

col

vector of length two (if all values of x are non-positive or all are non-negative; note that also a vector of length three is allowed in this case) or three (if x contains negative and positive values) providing the color key's default colors.

col.regions

see levelplot(). If NULL, a useful default is computed based on at.

…

additional arguments passed to the underlying levelplot().

Value

The plot, a Trellis object.

Details

Plot of a matrix.

Examples

# NOT RUN {
## Generate a random correlation matrix
d <- 50
L <- diag(1:d)
set.seed(271)
L[lower.tri(L)] <- runif(choose(d,2)) # random Cholesky factor
Sigma <- L 
# }
# NOT RUN {
<!-- %*% t(L) -->
# }
# NOT RUN {
P <- cor(Sigma)

## Default
matrix_plot(P)
matrix_plot(abs(P)) # if nonnegative
L. <- L
diag(L.) <- NA
matrix_plot(L.) # Cholesky factor without diagonal

## Default if nonpositive
matrix_plot(-abs(P))

## Extending the color key to [-1,1] with darker color for |rho| >> 0
## Note: When specifying 'at', one most likely also wants 'col.regions'
matrix_plot(P, at = seq(-1, 1, length.out = 200),
            col.regions = grey(c(seq(0, 1, length.out = 100), seq(1, 0,
                                     length.out = 100))))

## An example with overlaid lines
library(lattice)
my_panel <- function(...) {
    panel.levelplot(...)
    panel.abline(h = c(10, 20), v = c(10, 20), lty = 2)
}
matrix_plot(P, panel = my_panel)
# }