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copied!<p>This is an interesting problem - I'm curious to see other thoughts on this. Looking at the source for <code>table()</code> reveals that it builds off of <code>tabulate()</code>. <code>tabulate()</code> has a few quirks apparently, namely that it only deals with positive integers and returns an integer vector without names. We can use <code>unique()</code> on our vector to apply the <code>names()</code>. If you need to tabulate zero or negative values, I guess going back and reviewing <code>table()</code> would be necessary as <code>tabulate()</code> doesn't seem to do that per the examples on the help page.</p> <pre><code>table2 <- function(data) { x <- tabulate(data) y <- sort(unique(data)) names(x) <- y return(x) } </code></pre> <p>And a quick test:</p> <pre><code>> set.seed(42) > sampData <- sample(1:5, 10000000, TRUE, prob = c(.3,.25, .2, .15, .1)) > > system.time(table(sampData)) user system elapsed 4.869 0.669 5.503 > system.time(table2(sampData)) user system elapsed 0.410 0.200 0.605 > > table(sampData) sampData 1 2 3 4 5 2999200 2500232 1998652 1500396 1001520 > table2(sampData) 1 2 3 4 5 2999200 2500232 1998652 1500396 1001520 </code></pre> <p>EDIT: I just realized there is a <code>count()</code> function in <code>plyr</code> which is another alternative to <code>table()</code>. In the test above, it performs better than <code>table()</code>, and slightly worse than the hack-job solution I put together:</p> <pre><code>library(plyr) system.time(count(sampData)) user system elapsed 1.620 0.870 2.483 </code></pre>

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