title: R multiple choice questionnaire data to ggplot
body: <p>I have a Qualtrics multiple choice question that I want to use to create graphs in R. My data is organized so that you can answer multiple answers for each question. For example, participant 1 selected multiple choice answers 1 (Q1_1) &amp; 3 (Q1_3). I want to collapse all answer choices in one bar graph, one bar for each multiple response option (Q1_1:Q1_3) divided by the number of respondents who answered this question (in this case, 3). </p>
  
  <pre><code>df &lt;- structure(list(Participant = 1:3, A = c("a", "a", ""), B = c("", "b", "b"), C = c("c", "c", "c")), .Names = c("Participant", "Q1_1", "Q1_2", "Q1_3"), row.names = c(NA, -3L), class = "data.frame")
  </code></pre>
  
  <p>I want to use ggplot2 and maybe some sort of loop through Q1_1: Q1_3?</p>