title: Unable to run ur.df on a specific function
body: <p>I am just trying to run <code>ur.df</code> on a specific set of information, but it keeps saying that it is not a vector, or matrix, even though it is a sequential set of information.</p>
  
  <p>Code:</p>
  
  <pre><code>library(ggplot2)
  
  library(forecast)
  
  library(urca)
  
  library(vars)
  
  library(Metrics)
  
  library(tseries)
  
  library(fUnitRoots)
  
  vecm = ca.jo(df_level, type= c("eigen"), ecdet= c("const"), K=2, spec= c("transitory"))
  
  vecm.rls &lt;- cajorls(vecm, r = 1)
  
  error &lt;- vecm.rls$rlm$model['ect1']
  
  structure(list(ect1 = c(-0.167123621200091, 0.0355886318325172, 
          -0.0551981508361803, -0.120115360368026, -0.270394846503358, 
          -0.234452854475312)), .Names = "ect1", row.names = c(NA, 6L), class = "data.frame")
  
  errorADF = ur.df(error, type = c('none'), lags = 1, selectlags = c('Fixed'))
  
  summary(errorADF)
  </code></pre>
  
  <p>(btw, total novice here and this is for a final project.)</p>