rails: organizing data into a table using for - ruby-on-rails

Question

I have the following view:
<table class="fixed">
<tr>
<th>Student Name</th>
<!-- create as many <th> as there are evaluations -->
<% #eval_count.times do |i| %>
<th>Evaluation <%= i+1 %></th>
<% end %>
<th>Student Average <br />(for this goal)</th>
</tr>
<% for eval in #evals %>
<tr class="<%= cycle("odd", "even", name: "evals")%>">
<!-- eval returns { s_id [eval],[eval]} -->
<td><%= eval[1].first.student.name%></td>
<!-- in each student's row, print the score for each consecutive evaluation -->
<% #eval_count.times do |i| %>
<td><%= eval[1][i].score %><% #ss_scores << eval[1][i].score %></td>
<% end %>
<td><%= #ss_scores %></td>
</tr>
<% reset_cycle("evals") %>
<% end %>
</table>
<% #ss_scores.in_groups(#student_count, false) do |group|%>
<%= (group.sum.to_f/group.size).round(2) %>
<% end %>
which renders the following:
I want to put the average for each student in the last column, but #ss_scores is a variable and so calling anything on it doesn't work. But when the for loop has finished, #ss_scores can be worked with nicely as in the bottom of the screenshot. Any idea how to do this better?

Answer 1

Try emptying the array everytime, using [] and calculate the average inline, like below
<td><%= #ss_scores.inject(0.0) { |sum, el| sum + el } / #ss_scores.size %></td>
<% #ss_scores = [] %>
-
<% for eval in #evals %>
<tr class="<%= cycle("odd", "even", name: "evals")%>">
<!-- eval returns { s_id [eval],[eval]} -->
<td><%= eval[1].first.student.name%></td>
<!-- in each student's row, print the score for each consecutive evaluation -->
<% #eval_count.times do |i| %>
<td><%= eval[1][i].score %>
<% #ss_scores << eval[1][i].score %>
</td>
<% end %>
<td><%= #ss_scores.inject(0.0) { |sum, el| sum + el } / #ss_scores.size %></td>
<% #ss_scores = [] %>
</tr>
<% reset_cycle("evals") %>
<% end %>