R plot.xts error bars <p>Trying to put error bars on a time series plot using <code>plot.xts</code></p> <pre><code>&gt; myTS[1:20] [,1] 2013-07-01 29 2013-07-03 24 2013-07-03 16 2013-07-03 16 2013-07-03 12 2013-07-03 12 2013-07-03 16 2013-07-03 21 2013-07-03 21 2013-07-03 16 2013-07-05 12 2013-07-05 12 2013-07-05 12 2013-07-05 12 2013-07-08 16 2013-07-08 23 2013-07-08 16 2013-07-08 12 2013-07-09 16 2013-07-09 12 </code></pre> <p>I've aggregated this using <code>myTSquarterly = apply.quarterly(myTS,mean)</code></p> <pre><code>&gt; myTSquarterly [,1] 2013-09-30 24.50829 2013-12-31 23.79624 2014-03-31 24.15170 2014-06-30 24.57641 2014-09-30 23.71467 2014-12-31 22.99500 2015-03-31 24.50423 2015-06-30 25.19950 2015-09-30 24.76330 2015-12-31 24.65810 2016-03-31 25.35616 2016-06-30 22.71066 2016-07-27 20.63636 </code></pre> <p>I can plot easily using <code>plot.xts(myTSquarterly)</code>:</p> <p><a href="https://i.stack.imgur.com/fOXD8.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fOXD8.png" alt="enter image description here"></a></p> <p>I can calculate standard deviation easily as well with <code>apply.quarterly(myTS,sd)</code></p> <p>I would like to add these standard deviation info as error bars to the plot, but I cannot find a method for this?</p>