Plot Function for Block-Structured Precision Matrices (Visualize a Matrix with Group Boundaries)

Visualize a precision matrix as a heatmap with dashed boundary lines separating group blocks. This function is shared by objects returned from grasps, gen_prec_sbm, and sparsify_block_banded, all of which inherit from the S3 class "blkmat".

Usage

# S3 method for class 'blkmat'
plot(x, colors = NULL, ...)

Arguments

x

An object inheriting from S3 class "blkmat", typically returned by grasps, gen_prec_sbm or sparsify_block_banded.

colors

A vector of colors specifying an n-color gradient scale for the fill aesthetics.

...

Additional arguments passed to ggplot.

Value

A heatmap of class ggplot showing the matrix entries. Dashed lines indicate group boundaries. The plot title also reports matrix dimension and sparsity.

Examples

library(grasps)

## reproducibility for everything
set.seed(1234)

## block-structured precision matrix based on SBM
sim <- gen_prec_sbm(d = 100, K = 10,
                    within.prob = 0.2, between.prob = 0.05,
                    weight.dists = list("gamma", "unif"),
                    weight.paras = list(c(shape = 100, scale = 10),
                                        c(min = 0, max = 5)),
                    cond.target = 100)

## visualization
plot(sim)