<p>Prezados colegas,</p>
<div>Como faço para criar uma variável em um dataframe que seja soma acumulada de outra variável?</div>
<div> </div>
<div>
<table style="WIDTH:160pt;BORDER-COLLAPSE:collapse" border="0" cellspacing="0" cellpadding="0" width="212">
<colgroup>
<col style="WIDTH:48pt" width="64">
<col style="WIDTH:56pt" span="2" width="74">
<tbody>
<tr style="HEIGHT:12.75pt" height="17">
<td style="BORDER-BOTTOM:#ece9d8;BORDER-LEFT:#ece9d8;BACKGROUND-COLOR:transparent;WIDTH:48pt;HEIGHT:12.75pt;BORDER-TOP:#ece9d8;BORDER-RIGHT:#ece9d8" class="xl65" height="17" width="64"><font face="MS Sans Serif">i</font></td>

<td style="BORDER-BOTTOM:#ece9d8;BORDER-LEFT:#ece9d8;BACKGROUND-COLOR:transparent;WIDTH:56pt;BORDER-TOP:#ece9d8;BORDER-RIGHT:#ece9d8" class="xl65" width="74"><font face="MS Sans Serif">Xi</font></td>
<td style="BORDER-BOTTOM:#ece9d8;BORDER-LEFT:#ece9d8;BACKGROUND-COLOR:transparent;WIDTH:56pt;BORDER-TOP:#ece9d8;BORDER-RIGHT:#ece9d8" class="xl65" width="74"><font face="MS Sans Serif">Yi</font></td></tr>
<tr style="HEIGHT:12.75pt" height="17">
<td style="BORDER-BOTTOM:#ece9d8;BORDER-LEFT:#ece9d8;BACKGROUND-COLOR:transparent;HEIGHT:12.75pt;BORDER-TOP:#ece9d8;BORDER-RIGHT:#ece9d8" class="xl65" height="17"><font face="MS Sans Serif">1</font></td>
<td style="BORDER-BOTTOM:#ece9d8;BORDER-LEFT:#ece9d8;BACKGROUND-COLOR:transparent;BORDER-TOP:#ece9d8;BORDER-RIGHT:#ece9d8" class="xl65"><font face="MS Sans Serif">a</font></td>
<td style="BORDER-BOTTOM:#ece9d8;BORDER-LEFT:#ece9d8;BACKGROUND-COLOR:transparent;BORDER-TOP:#ece9d8;BORDER-RIGHT:#ece9d8" class="xl65"><font face="MS Sans Serif">a</font></td></tr>
<tr style="HEIGHT:12.75pt" height="17">
<td style="BORDER-BOTTOM:#ece9d8;BORDER-LEFT:#ece9d8;BACKGROUND-COLOR:transparent;HEIGHT:12.75pt;BORDER-TOP:#ece9d8;BORDER-RIGHT:#ece9d8" class="xl65" height="17"><font face="MS Sans Serif">2</font></td>
<td style="BORDER-BOTTOM:#ece9d8;BORDER-LEFT:#ece9d8;BACKGROUND-COLOR:transparent;BORDER-TOP:#ece9d8;BORDER-RIGHT:#ece9d8" class="xl65"><font face="MS Sans Serif">b</font></td>
<td style="BORDER-BOTTOM:#ece9d8;BORDER-LEFT:#ece9d8;BACKGROUND-COLOR:transparent;BORDER-TOP:#ece9d8;BORDER-RIGHT:#ece9d8" class="xl65"><font face="MS Sans Serif">a+b</font></td></tr>
<tr style="HEIGHT:12.75pt" height="17">
<td style="BORDER-BOTTOM:#ece9d8;BORDER-LEFT:#ece9d8;BACKGROUND-COLOR:transparent;HEIGHT:12.75pt;BORDER-TOP:#ece9d8;BORDER-RIGHT:#ece9d8" class="xl65" height="17"><font face="MS Sans Serif">3</font></td>
<td style="BORDER-BOTTOM:#ece9d8;BORDER-LEFT:#ece9d8;BACKGROUND-COLOR:transparent;BORDER-TOP:#ece9d8;BORDER-RIGHT:#ece9d8" class="xl65"><font face="MS Sans Serif">c</font></td>
<td style="BORDER-BOTTOM:#ece9d8;BORDER-LEFT:#ece9d8;BACKGROUND-COLOR:transparent;BORDER-TOP:#ece9d8;BORDER-RIGHT:#ece9d8" class="xl65"><font face="MS Sans Serif">a+b+c</font></td></tr></tbody></colgroup></table></div>
<div> </div>
<div>Obrigado.</div>