title: Aggregating a data frame with multiple type columns (character and numeric)
body: <p>I have 7 columns lets say A-G.  In a data frame of 100s to 1000s of entries/observations.  Column A-E &amp; G have duplicates and Column F has new data.  I want to aggregate or combine all these into on row summing Column F.</p>
  <p>I have tried <code>aggregate</code> and <code>group_by</code> and results are not as desired.</p>
  <pre><code>A           B   C         D         E            F       G
  IP1260341   1   6415504 26621   P1RRRRZ9999930S 412.25  LIS
  IP1260224   1   6415504 26621   P1RRRRZ9999930S 208     LIS
  IP1258742   1   6415504 25235   P1RRRRS0003300S 2775.58 LIS
  IP1257207   1   6415504 25723   P1RRRRS0003400S 108     LIS
  IP1259352   1   6415504 25235   P1RRRRS0003400S 150     LIS
  IP1259623   1   6W98W09 25223   EMPL-05104NCTR  925     LIS
  IP1260241   1   6415504 25235   P1RRRRS0003400S 360     LIS
  IP1257207   1   6415504 25723   P1RRRRS0003400S 108     LIS
  IP1259335   1   6415504 26335   P1RRRRP0016600S 9.64    LIS
  </code></pre>
  <p>The one below is an example of duplicate data that I need to aggregate column F</p>
  <pre><code>IP1259489   1   6415504 25435   P1RRRRS0003500S 196.8   LIS
  IP1259489   1   6415504 25435   P1RRRRS0003500S 166.8   LIS
  IP1259489   1   6415504 25435   P1RRRRS0003500S 572.4   LIS
  IP1259489   1   6415504 25435   P1RRRRS0003500S 40      LIS
  
  IP1260846   1   6999DFM 26509   14CDERS0078900S 23.75   UCH
  IP1260846   1   6999DFM 26509   14CDERS0078900S 1980    UCH
  IP1260967   1   6415544 26621   19PHCEE0769501S 283.36  UCH
  IP1260746   1   6415515 26509   P1RRRRE0006900S 248     UCH
  IP1260846   1   6999DFM 26509   14CDERS0078900S 699.65  UCH
  IP1260849   1   6999DFM 25732   14CDERS0078900S 711.3   UCH
  </code></pre>