This should get you started:

    R&gt; qplot(hwy, cty, data = mpg) + 
           facet_grid(. ~ manufacturer) + 
           theme(strip.text.x = element_text(size = 8, colour = &quot;orange&quot;, angle = 90))

See also this question: [How can I manipulate the strip text of facet plots in ggplot2?][1]


  [1]: https://stackoverflow.com/questions/2751065/how-can-i-manipulate-the-strip-text-of-facet-plots-in-ggplot2/2751201#2751201

I&#39;m using MongoDB in a reporting system and have to delete a whole bunch of test documents.  While I don&#39;t have too much trouble using the JSON-based command-line tools, it gets extremely tedious to have to keep searching for documents, copy-and-pasting OIDs, etc., *especially* from a command prompt window (ever tried to &quot;mark&quot; text that wraps multiple lines?)

How can I visually inspect the databases and collections, perform some simple CRUD tasks and manage multiple scripts in a proper window (not a command prompt)?

Visually managing MongoDB documents and collections

How do I track what position an element is when its position in a sortable list changes? 

jQuery UI Sortable Position

Is there a way to change the font size of facet labels in `ggplot`? I googled and found that the issue was yet on Hadley&#39;s to-do list. I wonder if there is a workaround or any news on this issue?



facet label font size

<p>Is there a way to change the font size of facet labels in <code>ggplot</code>? I googled and found that the issue was yet on Hadley's to-do list. I wonder if there is a workaround or any news on this issue?</p>


I want to split a data frame into several smaller ones. This looks like a very trivial question, however I cannot find a solution from web search.

How to split a data frame?

When installing rJava using the `install.packages(&quot;rJava&quot;)` command I get the following error:

    checking Java support in R... present:
    interpreter : &#39;/usr/bin/java&#39;
    archiver    : &#39;/usr/bin/jar&#39;
    compiler    : &#39;/usr/bin/javac&#39;
    header prep.: &#39;/usr/bin/javah&#39;
    cpp flags   : &#39;-I/usr/lib/jvm/java-6-sun-1.6.0.20/jre/../include -I/usr/lib/jvm/java-6-sun-1.6.0.20/jre/../include/linux&#39;
    java libs   : &#39;-L/usr/lib/jvm/java-6-sun-1.6.0.20/jre/lib/amd64/server -L/usr/lib/jvm/java-6-sun-1.6.0.20/jre/lib/amd64 -L/usr/lib/jvm/java-6-sun-1.6.0.20/jre/../lib/amd64 -L -L/usr/java/packages/lib/amd64 -L/usr/lib64 -L/lib64 -L/lib -L/usr/lib -ljvm&#39;
    checking whether JNI programs can be compiled... yes
    checking JNI data types... configure: error: One or more JNI types differ from the corresponding native type. You may need to use non-standard compiler flags or a different compiler in order to fix this.
    ERROR: configuration failed for package ‘rJava’

I have the Java JDK installed and `java -version` returns the following:

    $ java -version
    java version &quot;1.6.0_20&quot;
    Java(TM) SE Runtime Environment (build 1.6.0_20-b02)

When Googling around for the error I see that others are having the same issue but not finding a solution other than &quot;install the whole JDK, not just the JRE&quot; which I have done. 

The other thing I read was to run `sudo R CMD javareconf` which runs quite happily with no errors. 

Any ideas what my problem is? 

**[[EDIT]]**
It&#39;s been a few months since I had this problem. I had initially solved this by editing my Java paths, as illustrated in the answer I posted below. I recently ran into the same issue on a new Ubuntu install. I tried Dirk&#39;s recommendation to use apt-get to install the rJava package. It worked perfectly. What I failed to appreciate initially is that installing packages using the Ubuntu apt-get method is fundamentally different than just loading the same package using install.packages() inside of R. The Ubuntu packages solve some issues which I didn&#39;t realize or appreciate. 


R: rJava package install failing

I have a date in R, e.g.:

    dt = as.Date(&#39;2010/03/17&#39;)

I would like to subtract 2 years from this date, without worrying about leap years and such issues, getting `as.Date(&#39;2010-03-17&#39;)`.

How would I do that?

How to subtract years?

I have to split a vector into n chunks of equal size in R. I couldn&#39;t find any base function to do that. Also Google didn&#39;t get me anywhere. Here is what I came up with so far;

    x &lt;- 1:10
    n &lt;- 3
    chunk &lt;- function(x,n) split(x, factor(sort(rank(x)%%n)))
    chunk(x,n)
    $`0`
    [1] 1 2 3
    
    $`1`
    [1] 4 5 6 7
    
    $`2`
    [1]  8  9 10



Split a vector into chunks

I have a data frame containing (in random places) a character value (say `&quot;foo&quot;`) that I want to replace with a `NA`.

What&#39;s the best way to do so across the whole data frame?


Replacing character values with NA in a data frame

I have used the following `ggplot` command:

	ggplot(survey, aes(x = age)) + stat_bin(aes(n = nrow(h3), y = ..count.. / n), binwidth = 10)
	  + scale_y_continuous(formatter = &quot;percent&quot;, breaks = c(0, 0.1, 0.2))
	  + facet_grid(hospital ~ .)
	  + theme(panel.background = theme_blank())

to produce

![alt text][1]

I&#39;d like to change the *facet* labels, however, to something shorter (like `Hosp 1`, `Hosp 2`...) because they are too long now and look cramped (increasing the height of the graph is not an option, it would take too much space in the document). I looked at the [facet_grid][2] help page but cannot figure out how.

  [1]: https://imgur.com/lXK7C.png
  [2]: https://ggplot2.tidyverse.org/reference/facet_grid.html

How to change facet labels?

I plot the following:

    library(ggplot2)    

    carrots &lt;- data.frame(length = rnorm(500000, 10000, 10000))
    cukes &lt;- data.frame(length = rnorm(50000, 10000, 20000))
    carrots$veg &lt;- &#39;carrot&#39;
    cukes$veg &lt;- &#39;cuke&#39;
    vegLengths &lt;- rbind(carrots, cukes)

    ggplot(vegLengths, aes(length, fill = veg)) +
     geom_density(alpha = 0.2)

Now say, I only want to plot the region between `x=-5000` to `5000`, instead of the entire range.

How can I do that?

How to set limits for axes in ggplot2 R plots?

I have several faceted histograms (obtained with the command below) which are nicely plotted one under the other. I would like to increase the spacing between them, however, they are tight.

I looked at the [doc][1] but didn&#39;t find a parameter for this. 



    qplot (Happiness.Level, Number.of.Answers, data=mydata, geom=&quot;histogram&quot;) + facet_grid (Location ~ .) 


  [1]: http://had.co.nz/ggplot2/facet_grid.html

ggplot: How to increase spacing between faceted plots?

In the following example, how do I get the y-axis limits to scale according to the data in each panel?

    mt &lt;- ggplot(mtcars, aes(mpg, wt, colour = factor(cyl))) + geom_point() 

Neither of these will do it:

    mt + facet_grid(. ~ cyl, scales=&quot;free&quot;)
    mt + facet_grid(. ~ cyl, scales=&quot;free_y&quot;)





ggplot2, facet_grid, free scales?

I&#39;m plotting a categorical variable and instead of showing the counts for each category value.

I&#39;m looking for a way to get `ggplot` to display the percentage of values in that category. Of course, it is possible to create another variable with the calculated percentage and plot that one, but I have to do it several dozens of times and I hope to achieve that in one command.

I was experimenting with something like 

    qplot(mydataf) +
      stat_bin(aes(n = nrow(mydataf), y = ..count../n)) +
      scale_y_continuous(formatter = &quot;percent&quot;)

but I must be using it incorrectly, as I got errors.

To easily reproduce the setup, here&#39;s a simplified example:

    mydata &lt;- c (&quot;aa&quot;, &quot;bb&quot;, NULL, &quot;bb&quot;, &quot;cc&quot;, &quot;aa&quot;, &quot;aa&quot;, &quot;aa&quot;, &quot;ee&quot;, NULL, &quot;cc&quot;);
    mydataf &lt;- factor(mydata);
    qplot (mydataf); #this shows the count, I&#39;m looking to see % displayed.

In the real case, I&#39;ll probably use `ggplot` instead of `qplot`, but the right way to use [stat_bin][1] still eludes me.

I&#39;ve also tried these four approaches:

    ggplot(mydataf, aes(y = (..count..)/sum(..count..))) + 
      scale_y_continuous(formatter = &#39;percent&#39;);

    ggplot(mydataf, aes(y = (..count..)/sum(..count..))) + 
      scale_y_continuous(formatter = &#39;percent&#39;) + geom_bar();

    ggplot(mydataf, aes(x = levels(mydataf), y = (..count..)/sum(..count..))) + 
      scale_y_continuous(formatter = &#39;percent&#39;);
    
    ggplot(mydataf, aes(x = levels(mydataf), y = (..count..)/sum(..count..))) + 
      scale_y_continuous(formatter = &#39;percent&#39;) + geom_bar();

but all 4 give:

&gt;     Error: ggplot2 doesn&#39;t know how to deal with data of class factor

The same error appears for the simple case of 

    ggplot (data=mydataf, aes(levels(mydataf))) +
      geom_bar()

so it&#39;s clearly something about how `ggplot` interacts with a single vector. I&#39;m scratching my head, googling for that error gives a single [result][2]. 


  [1]: http://had.co.nz/ggplot2/stat_bin.html
  [2]: http://groups.google.com/group/ggplot2/browse_thread/thread/0489a702f3afc83b

Content Type	Original Author	Original Content on Stackoverflow
Question	Matt Bannert	View Question on Stackoverflow
Solution 1 - R	rcs	View Answer on Stackoverflow

facet label font size

R Problem Overview

R Solutions

Solution 1 - R

jQuery UI Sortable Position

Visually managing MongoDB documents and collections

Attributions