title: R programming : Error in Evaluate : Unused arguments
body: <p>I am new in R. <br/>
  I am using R language to build prototype for Recommendation System using <code>recommenderlab</code> package.<br/>
  I am getting below error message.</p>
  
  <pre><code>Error in evaluate(x = eval_sets, method = models_to_evaluate, n = n_recommendations) : 
    unused arguments (x = eval_sets, method = models_to_evaluate, n = n_recommendations)
  </code></pre>
  
  <p>On executing below code :</p>
  
  <pre><code>library(recommenderlab)
  library(ggplot2)
  data("MovieLense")
  ratings_movies &lt;- MovieLense[rowCounts(MovieLense) &gt; 27, colCounts(MovieLense) &gt; 21]
  n_fold &lt;- 4
  items_to_keep &lt;- 15
  rating_threshold &lt;- 3
  eval_sets &lt;- evaluationScheme(data = ratings_movies,
                                method = "cross-validation",
                                k = n_fold,
                                given = items_to_keep,
                                goodRating = rating_threshold)
  
  models_to_evaluate &lt;- list(
    IBCF_cos = list(name = "IBCF", param = list(method = "cosine")),
    IBCF_cor = list(name = "IBCF", param = list(method = "pearson")),
    UBCF_cos = list(name = "UBCF", param = list(method = "cosine")),
    UBCF_cor = list(name = "UBCF", param = list(method = "pearson")),
    random = list(name = "RANDOM", param=NULL)
  )
  
  n_recommendations &lt;- c(1, 5, seq(10, 100, 10))
  
  list_results &lt;- evaluate(x = eval_sets,
                      method = models_to_evaluate,
                      n = n_recommendations)
  </code></pre>
  
  <p>I am not sure why the error is coming and how can I fix this.
  <br/>
  I will be very thankful if somebody can help me out with this.<br/>
  Thanks in advance.</p>