title: SD of clusters (k-means)
body: <p>I am trying to find out how to get SD of my clusters gain my k-means cluster analysis. 
  I made the k-means and get several outputs, one of it are "centers" what I assume are means. I need standard deviations of all these centers to present my data and I don´t know, how to get them?</p>
  
  <pre><code>#kmeans
  resultspoorT0t &lt;- kmeans(poor_T0v, 3)
  resultspoorT0t[["centers"]]
  
         ALH      BCF      LIN       VAP       VCL      VSL
  1 5.130483 12.66909 40.14618  69.78680 146.97313 55.51221
  2 3.098673 10.11618 34.38605  29.20927  69.74657 22.70321
  3 7.212529 12.98836 41.71680 111.67745 229.73901 92.12502
  </code></pre>
  
  <p>I tried simple <code>sd()</code>function, but that makes one SD, I need SD for every parameter of every cluster</p>
  
  <pre><code>#SD
  sd(resultspoorT0t$cluster, na.rm = FALSE)
  [1] 0.758434
  </code></pre>