title: Rowsums isn't adding correctly?
body: <p>I have a presence absence database with a bunch of zeroes and ones, but when i use rowsums, it seems to only count a portion of the data and then stop. Here's my code </p>
  
  <pre><code>site_matrix=read.csv("TriassicMatrix1.csv", header=T) # create object called site_matrix
  summary(site_matrix) # get summary
  head(site_matrix) # check out first few columns
  tail(site_matrix) # check out last few columns
  View(site_matrix) # take a look at whole dataset in new window
  
  # here's the problematic line 
  
  spp_rich=rowSums(site_matrix [,2:25]) # generate richness for sites
  </code></pre>
  
  <p>There are 25 rows of data, and it gives me incorrect output, such as suggesting the first row only has 4 occurances when it has 7.</p>
  
  <p>I tried changing it to [,1,25]  and it won't work since row 1 is my title row, so I know it's not that. When I view the data within R i can very easily go to row 2 and count out the data, since there is only a few hundred columns. </p>
  
  <p>It appears to be 'cutting off' at about the halfway point, column-wise. </p>