Exclude columns by names in mutate_at in dplyr : <p>I am trying to do something very simple, and yet can't figure out the right way to specify. I simply want to exclude some named columns from <code>mutate_at</code>. It works fine if I specify position, but I don't want to hard code positions.</p>

<p>For example, I want the same output as this:</p>

<pre><code>mtcars %&gt;% mutate_at(-c(1, 2), max)
</code></pre>

<p>But, by specifying <code>mpg</code> and <code>cyl</code> column names.</p>

<p>I tried many things, including:</p>

<pre><code>mtcars %&gt;% mutate_at(-c('mpg', 'cyl'), max)
</code></pre>

<p>Is there a way to work with names and exclusion in <code>mutate_at</code>?</p>
