title: In R, what does the error "need at least one panel" mean and how to fix it?
body: <p>The following code is from the book "R in Action", listing 16.1:</p>
  
  <pre><code>library(lattice)
  attach(mtcars)
  
  gear &lt;- factor(gear, levels=c(3, 4, 5),
                 labels=c("3 gears", "4 gears", "5 gears"))
  cyl &lt;- factor(cyl, levels=c(4, 6, 8),
                labels=c("4 cylinders", "6 cylinders", "8 cylinders"))
  
  densityplot(~mpg,
              main="Density Plot",
              xlab="Miles per Gallon")
  
  densityplot(~mpg | cyl,
              main="Density Plot by Number of Cylinders",
              xlab="Miles per Gallon")
  
  bwplot(cyl ~ mpg | gear,main="Box Plots by Cylinders and Gears",
         xlab="Miles per Gallon", ylab="Cylinders")
  
  
  xyplot(mpg ~ wt | cyl * gear,
         main="Scatter Plots by Cylinders and Gears",
         xlab="Car Weight", ylab="Miles per Gallon")
  
  cloud(mpg ~ wt * qsec | cyl,
        main="3D Scatter Plots by Cylinders")
  
  dotplot(cyl ~ mpg | gear,
          main="Dot Plots by Number of Gears and Cylinders",
          xlab="Miles Per Gallon")
  
  splom(mtcars[c(1, 3, 4, 5, 6)],
        main="Scatter Plot Matrix for mtcars Data")
  
  detach(mtcars)
  </code></pre>
  
  <p>I am able to plot only the first density plot and the last plot, splom(...). The rest of the plots give me the following error:</p>
  
  <blockquote>
    <p>Error in limits.and.aspect(default.prepanel, prepanel = prepanel, have.xlim = have.xlim,  : 
      need at least one panel</p>
  </blockquote>
  
  <p>What does this error mean and how do I fix it?</p>
  
  <p>I have just started learning R and the version I am using is:</p>
  
  <pre><code>R version 3.1.0 (2014-04-10)
  Platform: x86_64-w64-mingw32/x64 (64-bit)
  
  locale:
  [1] LC_COLLATE=English_Malaysia.1252  LC_CTYPE=English_Malaysia.1252   
  [3] LC_MONETARY=English_Malaysia.1252 LC_NUMERIC=C                     
  [5] LC_TIME=English_Malaysia.1252    
  
  attached base packages:
  [1] stats     graphics  grDevices utils     datasets  methods   base     
  
  other attached packages:
  [1] lattice_0.20-29
  
  loaded via a namespace (and not attached):
  [1] grid_3.1.0
  </code></pre>
  
  <p>EDIT:</p>
  
  <p>Output of search() is:</p>
  
  <pre><code> [1] ".GlobalEnv"        "mtcars"            "package:lattice"  
   [4] "package:stats"     "package:graphics"  "package:grDevices"
   [7] "package:utils"     "package:datasets"  "package:methods"  
  [10] "Autoloads"         "package:base"  
  </code></pre>