# How to visualize NaNs in an array?

**URL:** https://discourse.julialang.org/t/how-to-visualize-nans-in-an-array/133738
**Category:** General Usage
**Tags:** question
**Created:** [November 7, 2025, 4:49pm UTC](https://discourse.julialang.org/t/how-to-visualize-nans-in-an-array/133738 "2025-11-07T16:49:32Z")
**Posts on this page:** 1
**Showing post:** 8

<div class="post-metadata">

### Author: ![rafael.guerra](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rafael.guerra/32/216610_2.png) [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)
#### Post date: [November 7, 2025, 7:04pm UTC](https://discourse.julialang.org/t/how-to-visualize-nans-in-an-array/133738/8 "2025-11-07T19:04:03Z")

</div>

Another REPL option, credit to @jd-foster ([this post](https://discourse.julialang.org/t/how-to-combine-prettytables-and-pager/85593/4)):

```julia
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)

```

 ![PrettyTables_TerminalPager_Matrix_with_red_NaN](https://global.discourse-cdn.com/julialang/original/3X/e/f/ef17f025b02574979b0fa67ef9621346f1a7792f.png)

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