title: R plot: size and resolution
body: <p>I have stacked into the question: I need to plot the image with DPI=1200 and specific print size.</p>
  
  <p>By default the png looks ok...
  <img src="https://i.stack.imgur.com/v51Aj.png" alt="enter image description here"></p>
  
  <pre><code>png("test.png",width=3.25,height=3.25,units="in",res=1200)
  par(mar=c(5,5,2,2),xaxs = "i",yaxs = "i",cex.axis=1.3,cex.lab=1.4)
  plot(perf,avg="vertical",spread.estimate="stddev",col="black",lty=3, lwd=3)
  dev.off()
  </code></pre>
  
  <p>But when I apply this code, the image became really terrible it's not scaling (fit) to the size that is needed. What did I miss? How to "fit" the image to the plot?</p>
  
  <p><img src="https://i.stack.imgur.com/sueTP.png" alt="enter image description here">,</p>