title: how can I reconstruct original data after using pca with svd in python?
body: <p>I apply pca in my data set.
  I use this code :</p>
  
  <p>Ap1 is my data after calculating mean on it.
  now I want to reconstruct my original data from this new component.
  what work should I do?
  thanks</p>
  
  <pre class="lang-py prettyprint-override"><code>pca = PCA(n_components=3).fit(Ap1)
  U = pca.components_          
  S = pca.explained_variance_ 
  </code></pre>