Plot Matrices Using a Color/Intensity Grid
Plots a matrix, m, associating the magnitude of the i,jth cell of m with the color of the i,jth cell of an nrow(m) by ncol(m) grid.
## S3 method for class 'sociomatrix'
plot(x, labels=NULL, drawlab=TRUE, diaglab=TRUE,
drawlines=TRUE, xlab=NULL, ylab=NULL, cex.lab=1, font.lab=1, col.lab=1,
scale.values=TRUE, cell.col=gray, ...)
sociomatrixplot(x, labels=NULL, drawlab=TRUE, diaglab=TRUE,
drawlines=TRUE, xlab=NULL, ylab=NULL, cex.lab=1, font.lab=1, col.lab=1,
scale.values=TRUE, cell.col=gray, ...)x |
an input graph. |
labels |
a list containing the vectors of row and column labels (respectively); defaults to the row/column labels of |
drawlab |
logical; add row/column labels to the plot? |
diaglab |
logical; label the diagonal? |
drawlines |
logical; draw lines to mark cell boundaries? |
xlab |
x axis label. |
ylab |
y axis label. |
cex.lab |
optional expansion factor for labels. |
font.lab |
optional font specification for labels. |
col.lab |
optional color specification for labels. |
scale.values |
logical; should cell values be affinely scaled to the [0,1] interval? (Defaults to |
cell.col |
function taking a vector of cell values as an argument and returning a corresponding vector of colors; defaults to |
... |
additional arguments to |
plot.sociomatrix is particularly valuable for examining large adjacency matrices, whose structure can be non-obvious otherwise. sociomatrixplot is an alias to plot.sociomatrix, and may eventually supersede it.
The cell.col argument can be any function that takes input cell values and returns legal colors; while gray will produce an error for cell values outside the [0,1] interval, user-specified functions can be employed to get other effects (see examples below). Note that, by default, all input cell values are affinely scaled to the [0,1] interval before colors are computed, so scale.values must be set to FALSE to allow access to the raw inputs.
None
Carter T. Butts buttsc@uci.edu
#Plot a small adjacency matrix
plot.sociomatrix(rgraph(5))
#Plot a much larger one
plot.sociomatrix(rgraph(100), drawlab=FALSE, diaglab=FALSE)
#Example involving a signed, valued graph and custom colors
mycolfun <- function(z){ #Custom color function
ifelse(z<0, rgb(1,0,0,alpha=1-1/(1-z)), ifelse(z>0,
rgb(0,0,1,alpha=1-1/(1+z)), rgb(0,0,0,alpha=0)))
}
sg <- rgraph(25) * matrix(rnorm(25^2),25,25)
plot.sociomatrix(sg, scale.values=FALSE, cell.col=mycolfun) #Blue pos/red negPlease choose more modern alternatives, such as Google Chrome or Mozilla Firefox.