title: Plotting PCA : way to label data points
body: <p>I can use Plot function. Could use plot to get the pca results. But not sure how to label these points according to my datapoints which are <code>rownames(Sample)</code> numbered 1 to 90</p>
  
  <pre><code>Sample&lt;-read.table(file.choose(),header=F,sep="\t")
  Sample.scaled&lt;-data.frame(apply(Sample_2XY,2,scale))
  Sample_scaled.2&lt;-data.frame(t(na.omit(t(Sample_2XY.scaled))))
  
  pca.Sample&lt;-prcomp(Sample_2XY.scaled.2,retx=TRUE)
  
  pdf("Sample_plot.pdf")
  plot(pca.Sample$x)
  dev.off()
  </code></pre>