title: Can't find function theme package ggplot2 R
body: <p>I am currently working on a Debian server (for my internship) and I'm using <code>ggplot2</code> to plot some graphics.</p>
  
  <p>So, I load the package by writing : <code>require(ggplot2)</code> (tried too<code>library(ggplot2)</code>, same result). However the function <code>theme</code> is not recognized (which is a function from <code>ggplot2</code>).</p>
  
  <p>To show you that the package has already been installed, here is an exemple of one of my graphic generated with <code>ggplot2</code> functions :</p>
  
  <ul>
  <li>The graphic : <a href="https://gyazo.com/83a6cac0829057da767a8a606491abfc" rel="noreferrer">https://gyazo.com/83a6cac0829057da767a8a606491abfc</a></li>
  <li>The message from the server : <a href="https://gyazo.com/a48e7afa5615175a8e12b7326e2748b6" rel="noreferrer">https://gyazo.com/a48e7afa5615175a8e12b7326e2748b6</a></li>
  </ul>
  
  <p>And here what I get when ploting a graphic with the function theme :</p>
  
  <ul>
  <li>Message from the server : <a href="https://gyazo.com/c171f2c3740dbea49736622d5a05c451" rel="noreferrer">https://gyazo.com/c171f2c3740dbea49736622d5a05c451</a></li>
  <li>The produced graphic on RStudio : <a href="https://gyazo.com/cf6e2dbee9a882087caad6c491084a32" rel="noreferrer">https://gyazo.com/cf6e2dbee9a882087caad6c491084a32</a></li>
  </ul>
  
  <p>The graphic can't be generated because he can't find the function theme. So I wanted to know if there are some tricks to load a function from a package, for example like that : <code>ggplot2.theme</code></p>
  
  <p>Or does it mean R is not properly installed on the server ? (we have followed the CRAN tutorial for Debian server : <a href="https://cran.r-project.org/bin/linux/debian/" rel="noreferrer">https://cran.r-project.org/bin/linux/debian/</a> + for information we have installed the package with the console by writing : <code>apt-get install r-cran-ggplot2</code>).</p>
  
  <pre><code>require(ggplot2)
  
  #Data
  data_y &lt;- c(14, 111, 4, 12, 80, 105, 120, 88, 108, 119)
  data_x &lt;- c("person1",
              "person2",
              "person3",
              "person4",
              "person5",
              "person6",
              "person7",
              "person8",
              "person9",
              "person10"
              )
  
  #Dataframe
  data_xy &lt;- data.frame(data_x, data_y)
  
  #Plot
  
  p &lt;- ggplot(data_xy, aes(data_x, data_y))
  p + geom_bar (
          stat = "identity", 
          fill = "steelblue1", 
          colour = "grey", 
          size = 1
          ) + 
  
      theme (
          axis.text.x=element_text(
              angle=45,
              hjust=0.5,
              vjust=0.5
              )
          ) +
    theme_bw()
  </code></pre>