Is there any way to get an objects array index as you loop through an array in Ruby?

I'm working with the following code where @ta is set as the array index:
Code:
<% @ta=0 %>
<% for article in @articles -%>
  <%= render_partial "article", article %>
  <% @ta+=1 %>
<% end -%>
This seems very primative to me and prone to errors. Is there anyway to do something like the following:
Code:
<% for article in @articles -%>
  <% @ta = article.index %>
  <%= render_partial "article", article %>
<% end -%>
I tried it but got an error.