title: String matching in R to return "does not contain" results
body: <p>I would like to drop all rows in my data frame where column A contain either a "_" or "(" or ")" and where column D does not contain "InService".</p>
  
  <p>I believe you can use grep or grepl for the contains section but I don't know how to tie it into my expression below.</p>
  
  <pre><code>Atoll &lt;- read.csv("ATOLL_TABLE20160803_084232.csv")
  AtollInService &lt;- Atoll[(Atoll$MILESTONE=="InService" &amp; grep(???)),]
  </code></pre>
  
  <p>Below is an example of the excel file I am importing, please note I've hidden a few columns since the data is spread across many fields. </p>
  
  <pre><code>NOMINAL_ID     MILESTONE
  WW_4752 (MD)    Planned
  WW_4752 (MD)    Planned
  WW_4752 (MD)    Planned
  LX0022 (OZ)     Planned
  LX0022 (OZ)     Planned
  LX0023          InService
  LX0023          InService
  LX0023          InService
  LX0023          InService
  LX0023          InService
  LX0023          InService
  </code></pre>
  
  <p>And below is what I am looking to achieve:</p>
  
  <pre><code>NOMINAL_ID      MILESTONE
  LX0023          InService
  LX0023          InService
  LX0023          InService
  LX0023          InService
  LX0023          InService
  LX0023          InService
  </code></pre>