title: Error: protect(): protection stack overflow
body: <p>i got an error while i am running a big data. Error has explained by the following sample sample </p>
  
  <p>Load data </p>
  
  <pre><code>   mdata &lt;- as.matrix(read.table('https://gubox.box.com/shared/static/qh4spcxe2ba5ymzjs0ynh8n8s08af7m0.txt', header = TRUE, check.names = FALSE, sep = '\t')) 
  </code></pre>
  
  <p>Install and load library </p>
  
  <pre><code>source("https://bioconductor.org/biocLite.R") 
  biocLite("impute") 
  library(impute)
  </code></pre>
  
  <p>Sets a limit on the number of nested expressions </p>
  
  <pre><code>options(expressions = 500000)
  </code></pre>
  
  <p>Apply k-nearest neighbors for missing value imputation </p>
  
  <pre><code>res &lt;-impute.knn(mdata)
  </code></pre>
  
  <p>and I got:</p>
  
  <blockquote>
    <p>Error: protect(): protection stack overflow</p>
  </blockquote>
  
  <p>If anybody has solution or suggestion, please share. 
  Thanks</p>