R strsplit() with multiple criteria
<p>I am trying to split sentences based on different criteria. I am looking to split some sentences after " is" and some after " never". I was able to split sentences based on either of these conditions but not both.</p>

<pre><code>str &lt;- matrix(c("This is line one", "This is not line one", 
                "This can never be line one"), nrow = 3, ncol = 1)

&gt;str
     [,1]                        
[1,] "This is line one"          
[2,] "This is not line one"      
[3,] "This can never be line one"

str2 &lt;- apply(str, 1, function (x) strsplit(x, " is", fixed = TRUE))

&gt; str2
[[1]]
[[1]][[1]]
[1] "This"      " line one"


[[2]]
[[2]][[1]]
[1] "This"          " not line one"


[[3]]
[[3]][[1]]
[1] "This can never be line one"
</code></pre>

<p>I would like to split the last sentence after " never". I am not sure how to do that.</p>