[r] Persistent invalid graphics state error when using ggplot2

I believe my dataframe is okay and my code is okay. In fact, I have eliminated parts of the dataframe and most of the graphing code to make things as basic as possible. But still, I get:

Error in .Call.graphics(C_palette2, .Call(C_palette2, NULL)) : 
  invalid graphics state

What is wrong here? Here is the data:

 date   trt var val
1/8/2008    cc  sw5 0.2684138
1/8/2008    cc  sw15    0.2897586
1/8/2008    cc  sw5 0.2822414
2/8/2008    cc  sw5 0.2494583
2/8/2008    cc  sw5 0.2692917
2/8/2008    cc  sw15    0.2619167
2/8/2008    cc  sw5 0.204375
3/8/2008    cc  sw5 0.2430625
3/8/2008    cc  sw5 0.2654375
3/8/2008    cc  sw5 0.2509583
3/8/2008    cc  sw5 0.2055625
1/8/2008    ccw sw15    0.2212414
1/8/2008    ccw sw5 0.3613448
1/8/2008    ccw sw5 0.2607586
2/8/2008    ccw sw5 0.2087917
2/8/2008    ccw sw15    0.3390417
2/8/2008    ccw sw5 0.2436458
2/8/2008    ccw sw5 0.290875
3/8/2008    ccw sw5 0.20175
3/8/2008    ccw sw15    0.328875
3/8/2008    ccw sw5 0.2328958
3/8/2008    ccw sw5 0.2868958

When I work with this data, I specify dates like this:

df<-df[order(as.Date(df$date,format="%d/%m/%Y")),,drop=FALSE]

and here I want to make a scatterplot:

ggplot(data = df,aes(x = date,y = val)) + 
 geom_point(aes(group = trt))

I found this to occur when you mix ggplot charts with plot charts in the same session. Using the 'dev.off' solution suggested by Paul solves the issue.

The solution is to simply reinstall ggplot2. Maybe there is an incompatibility between the R version you are using, and your installed version of ggplot2. Alternatively, something might have gone wrong while installing ggplot2 earlier, causing the issue you see.

try to get out grafics with x11() or win.graph() and solve this trouble.

I solved this by clearing all the plots in the console and then making sure the plot area was large enough to accommodate what I was creating.

You likely don't need to reinstall ggplot2

Solution: go back to plot that didn't work previously. Take the below console output for example. The figure margins (the window that displays your plots) were too small to display the pairs(MinusInner) plot. Then when I tried to make the next qplot, R was still hung up on previous error.

pairs(MinusInner) Error in plot.new() : figure margins too large qplot(Sample.Type, BAE,data=MinusInner, geom="boxplot") Error in .Call.graphics(C_palette2, .Call(C_palette2, NULL)) : invalid graphics state

I fixed the first error by expanding the plot window and rerunning the pairs(MinusInner) plot. Then blam, it worked.

pairs(MinusInner) qplot(Sample.Type, BAE,data=MinusInner, geom="boxplot")