title: scatterplot3d - change axis range
body: <p>I am using scatterplot3d to generate several plots, and I would like to keep the scales consistent throughout each of the plots (I am trying to show changes over time, so this is essential).  My current code is as follows (by no means elegant, as I am a beginner!):</p>
  
  <pre><code>library(scatterplot3d)
  file&lt;-read.csv("DAY2.csv")
  axis1&lt;-file$axis1
  axis2&lt;-file$axis2
  axis3&lt;-file$axis3
  s3d &lt;- scatterplot3d(axis1, axis2, axis3)
  colors &lt;- c("#9900FF", "#E69F00", "#339900", "#0000FF")
  colors &lt;- colors[as.numeric(file$treatment)]
  s3d &lt;- scatterplot3d(file[,1:3], pch = 16, color=colors, xlab =
  "Axis 1", ylab = "Axis 2", zlab = "Axis 3")
  legend(s3d$xyz.convert(0.4, 0.4, -0.1), col= c("#9900FF", "#E69F00", 
  "#339900", "#0000FF"), bg="white", lty=c(1,1), lwd=2, yjust=0,      
  legend = c("high perf", "low perf"), cex = 0.7)
  </code></pre>
  
  <p>Is it possible to specify axis ranges to keep these consistent between plots? I have checked the vignette, but there is no information in there on this.</p>
  
  <p>Thanks in advance,</p>
  
  <p>Jo</p>