title: Error in R Markdown (non-numeric argument to binary operator)
body: <p>I only get this error in attempting to knit in R Markdown to a Word document. The code runs fine elsewhere (in the Rscript).Also I have already had previous code showing:</p>
  
  <pre><code>numericScores = transform(correctedScores, beer2_score =     as.numeric(beer2_score))
  numericScores = transform(correctedScores, beer3_score = as.numeric(beer3_score))
  numericScores = transform(correctedScores, beer4_score = as.numeric(beer4_score))
  numericScores = transform(correctedScores, beer5_score = as.numeric(beer5_score))
  numericScores = transform(correctedScores, beer6_score = as.numeric(beer6_score))
  
  # testing to see if they are indeed numeric
   sapply(numericScores, mode)
  
  correctedGuesses = Guesses[complete.cases(Guesses), ]
  str(correctedGuesses)
  correctedGuesses
  
  correctedScores = numericScores[complete.cases(numericScores), ]
  str(correctedScores)
  correctedScores
  ########
  
  # trying to put scores in correct order 
  
  # first I will label the beers with their names
  
  for(i in 1:45){
    for(j in 2:7) {
  if (Order[i,j] == 1) { Order[i, j] = "Miller"}
  if (Order[i,j] == 2) { Order[i, j] = "Natural"}
  if (Order[i,j] == 3) { Order[i, j] = "Keystone"}
  if (Order[i,j] == 4) { Order[i, j] = "Busch"}
  if (Order[i,j] == 5) { Order[i, j] = "Bud"}
  if (Order[i,j] == 6) { Order[i, j] = "Miller"}
    } 
  }
  
  # Deleting the unused/unavailable Order rows
  Order = Order[-c(4, 33),]
  
  
  Miller_sc = 0 
  Natural_sc = 0
  Keystone_sc = 0
  Busch_sc = 0
  Bud_sc = 0
  
  B = c(
  Miller_sc, 
  Natural_sc,
  Keystone_sc,
  Busch_sc,
  Bud_sc )
  
  for (i in 1:43) {
   for (j in 2:7) {
  if (Order[i,j] == "Miller") {B[1] = B[1] + correctedScores[i,j]}
  if (Order[i,j] == "Natural") {B[2] = B[2] + correctedScores[i,j]}
  if (Order[i,j] == "Keystone") {B[3] = B[3] + correctedScores[i,j]}
  if (Order[i,j] == "Busch") {B[4] = B[4] + correctedScores[i,j]}
  if (Order[i,j] == "Bud") {B[5] = B[5] + correctedScores[i,j]}
   }
  }
  </code></pre>
  
  <p>The error reads: <br/></p>
  
  <blockquote>
    <p>Error in B[3] + correctedScores[i, j]: non-numeric argument to binary
    operator Calls:  ... handle ->withCallingHandlers ->
    withVisible -> eval -> eval Execution halted</p>
  </blockquote>