How to visualize NaNs in an array?

[rafael.guerra]

Another REPL option, credit to @jd-foster (this post):

using PrettyTables, TerminalPager

A = rand(150, 150);
A[A .< .1] .= NaN;

hl = TextHighlighter((d, i, j) -> isnan(d[i,j]), crayon"red")
io = IOContext(IOBuffer(), :color => true);
pretty_table(io, A, alignment=:r, display_size=(-1,-1), show_row_number_column=true, highlighters=[hl])
pager(String(take!(io.io)), frozen_columns=7, frozen_rows=3)