pan class='st'>"_"</span>,
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<span class='va'>tuneGrid</span><span class='op'>$</span><span class='va'>base</span> <span class='op'>&lt;-</span> <span class='fu'><a href='https://rdrr.io/r/base/paste.html'>paste0</a></span><span class='op'>(</span>
  <span class='fu'><a href='https://rdrr.io/r/base/c.html'>c</a></span><span class='op'>(</span><span class='st'>"linear"</span>, <span class='st'>"quad"</