title: How do I determine the number of significant figures in data in R?
body: <p>I have a large dataset that I'm analyzing in R and I'm interested in one column or vector of information. Each entry in this vector has a varied number (ranging from 1-5) of significant figures, and I want to subset this vector so I'm not seeing data with only one significant digit. What kind of test or function can I use to get R to report the number of significant figures for each entry? I've looked into the signif() function but that is more for rounding data to a specified number of significant digits, not querying how many sig figs are there.</p>
  
  <p>Example: Suppose I have this vector: <br/>
  4<br/>
  28.382<br/>
  120<br/>
  82.3<br/>
  100<br/>
  30.0003</p>
  
  <p>I want to remove the entries that only have one significant digit. That would be entries 1 (value of 4) and entry 5 (value of 100). I know how to subset data in R, but I don't know how to tell R to "find" all the values with only one significant figure.</p>