In JIRA wiki markup, how do I write O(n)?

[Borek Bernard]

We are discussing algoritmic complexity in one of our JIRA issues and I want to write something like this:

O(n²) or O(n)

However, JIRA superscript tags don't work for me (there is O(n^2^) in the output) and when I write O(n), it converts it to some stupid emoticon.

How do I write those things in JIRA wiki markup? Can I insert inline HTML? Can I disable smilies?

[tier-0 grump · Accepted solution]

You just nees a space in front of the ^ - so this will work O(n ^2^)

[Borek Bernard]

That creates O(n ²), not O(n²). Does it always work like that, that wiki formatting characters must be prepended by a space? Are the exact rules described somewhere?

[tier-0 grump]

Just saw the second part.simply escape the brackets O\(n\)

[tier-0 grump]

This is probably the best resource - although it doesn't say anything about spaces - https://jira.atlassian.com/secure/WikiRendererHelpAction.jspa?section=all

[Borek Bernard]

I've seen that but that is really very imprecise (it is a quick user guide rather than full documentation on all the rules). I'd be much happier if the markup was Markdown but I can that can't be intergrated with JIRA, can it?

[Lorenzo Solano Martinez]

See my answer, it solves the space problem (between 'n' and '2').

[Deleted user]

Like Björn Shad said below, enforce markup recognition by putting the markup in braces  : n{^}2^

The opposite is \^ .

[Björn Schad]

Obviously you need to have something not being a letter in front of the caret (superscript) or tilde (subscript) ... and many HTML entities exist. I would suggest &zwj; or the zero-wdith non-breakable space  (which does not have a nice entity reference).

Update: You can enforce markup recognition by putting caret or tilde into curly braces: n{^}2^.

[Lorenzo Solano Martinez]

Hi Borek,

Here you have: O(n^2^), renders as O(n²); the trick is to add the backspace HTML secuence in between the 'n' and the first caret.

To have n to the power of 2 you will need to write n^2^, now this doesn't work because the first caret is just after the 'n' and it needs to be after a space (or some other entities, unspecifed in JIRA's documentation). If you add a space between the 'n' and the first caret it works, but it is rendered as is, with the unwanted space in-between.

I did try several HTML codes but just the backspace ('') works. Don't ask my why becuase I don't fully understand the behaivor of the renderer, my guess is that this combination is a valid one to activate the superscript secuence.

Later, I did try with other html codes and found that the Delete char (#127), works in the same way that the backspace does (#08). Here you have 2 samples of writing the quadratic function. I found the same problem to put the 'X' bold, and solve it in the same way of the superscript.

A) Using backspace #08:

a*X*^2^ ± b*X* ± c = 0, a ≠ 0

It's rendered as: aX² ± bX ± c = 0, a ≠ 0

B) Using delete #127:

a*X*^2^ ± b*X* ± c = 0, a ≠ 0

It's rendered as: aX² ± bX ± c = 0, a ≠ 0

Lorenzo,