title: How to suppress the warning message for NaN values for groupings with only one observation when using the summarySE function in R?
body: <p>I'm creating a dashboard that utilises the summarySE function. This is working as expected so far, but I've noticed that the console window produces error messages when using this function on a table using a grouping which contains at least one group with only one observation in it. (This causes SD, SE, and CI to fail.)</p>
  <p>Is there a way to suppress error messages caused by this instance? This is not something I'm concerned about as I expect there to be some small groupings like that, but I don't want error messages to be produced unless I need to actually investigate something.</p>
  <p>As an example...</p>
  <pre><code>summarySE(head(iris),measurevar='Sepal.Width', groupvars=('Petal.Length'))
  </code></pre>
  <p>Only one grouping (Petal.Length = 1.4) has more than one observation. NA is produced under the relevant stats for the other groups with only one observation. The above function gives the following output:</p>
  <pre><code>  Petal.Length N Sepal.Width       sd        se        ci
  1          1.3 1    3.200000       NA        NA        NA
  2          1.4 3    3.366667 0.321455 0.1855921 0.7985386
  3          1.5 1    3.100000       NA        NA        NA
  4          1.7 1    3.900000       NA        NA        NA
  Warning message:
  In qt(conf.interval/2 + 0.5, datac$N - 1) : NaNs produced
  </code></pre>
  <p>I know there is a na.rm argument which you can set to TRUE/FALSE to ignore NA values but this doesn't seem to do anything that I can notice in this case.</p>
  <p>Does anyone know how to suppress this error?</p>