Add an answer column to a timeSeries in R
<p>After creating simple timeSeries object...</p>

<pre><code>data &lt;- matrix(rnorm(18), ncol = 3)
colnames(data) &lt;- LETTERS[1:3]
charvec &lt;- paste("2009-0", 1:6, "-01", sep = "")
s &lt;- timeSeries(data, charvec)
</code></pre>

<p>And, adding two columns together, What is the best code to include it as an additional column "D" in the timeSeries "s"? </p>

<pre><code>&lt;- s[,"B"] + s[,"C"]
</code></pre>