Where to put a label on a LaTeX figure

I just found out that LaTeX is sensitive as to where you put the label command in a figure environment. For example if you do something like this:

begin{figure}
  centering
  includegraphics[width=0.95columnwidth]{sompic}
  label{fig:some-pic}
  caption{Some caption.}
end{figure}

if you now do a ref{fig:some-pic}, the reference will point to the parent element of the figure environment. For me, I got a reference to the subsection enclosing the figure. This was very irritating, because the text then said “see Figure 3.4.2.4 for details.”
Instead you need to place the label in or after the caption command. For some reason the ref will then point to the figure: 

begin{figure}
  centering
  includegraphics[width=0.95columnwidth]{sompic}
  caption{Some caption.}
  label{fig:some-pic}
end{figure}

Update: And here is also the answer to the question why it is necessary to do it this way.

Another OS X git UI: SourceTree

Besides gitx, I now was shown another git user interface for OS X. It is called SourceTree:

It is more mature and feature-rich, compared to gitx. But it is closed source. However, it is free (as in beer) for the time being in the App Store. So far, the program seems really nice. Let’s see how long I will continue using it, and if I’ll go back to gitx at some point.

XCode 4 is incredibly slow

XCode 4 has always been incredibly slow for me. The first release, 4.0, was especially bad. But that was just a .0 version. The next release 4.1 is much better, but it has also severe drawbacks, concerning performance. Everytime I start it, and not even do much with it, my system gets incredibly slow. That is on both a C2D 2.8 GHz MBP and also on a quad-core i7 MBP. Both machines come with 4 GB of RAM, and after firing XCode up and loading a large project, still at least 500 MB of it remains free. However, speed is abysmal. I just found the tool vmmap in OS X, and it gives me this output:

==== Summary for process 32136
ReadOnly portion of Libraries: Total=265.8M resident=114.4M(43%) swapped_out_or_unallocated=151.5M(57%)
Writable regions: Total=16.2G written=149.6M(1%) resident=360.9M(2%) swapped_out=6156K(0%) unallocated=15.9G(98%)
REGION TYPE                      VIRTUAL
===========                      =======
CG backing stores                  19.4M
CG image                            268K
CG raster data                     2840K
CG shared images                   3472K
CoreAnimation                       180K
CoreGraphics                         16K
CoreImage                           108K
CoreServices                       1704K
IOKit                              61.2M
MALLOC                            337.4M        see MALLOC ZONE table below
MALLOC (reserved)                  15.6G        reserved VM address space (unallocated)
MALLOC freed, no zone              30.5M
MALLOC guard page                    64K
MALLOC metadata                   128.8M
Memory tag=240                        4K
Memory tag=242                       12K
Memory tag=243                        4K
Memory tag=249                      156K
Memory tag=251                       64K
OpenCL                               60K
OpenGL GLSL                        1372K
OpenGL GLSL (reserved)              128K        reserved VM address space (unallocated)
SQLite page cache                  14.6M
STACK GUARD                        56.1M
Stack                              19.7M
VM_ALLOCATE                        16.1M
__CI_BITMAP                          80K
__DATA                             33.9M
__IMAGE                            1256K
__LINKEDIT                         59.5M
__TEXT                            206.4M
__UNICODE                           544K
mapped file                        72.9M
shared memory                      13.6M
===========                      =======
TOTAL                              16.7G
TOTAL, minus reserved VM space      1.1G

So the virtual memory space that XCode takes is more than 16 GB! The actual memory taken is “only” 1.1 GB, which is still huge, but my Emacs also takes 500 MB with tons of C++, Python and LaTeX buffers open.
The question is: can the unallocated, but reserved 16 GB address space degrade the performance? I have too little knowledge of the workings of virtual memory on Intel CPUs under OS X. But this value seems incredibly huge.

Update: I have asked a question on Stackoverflow, and have gotten some useful answers. What did help was removing my build/ folder from the git. Accidentally, a colleague checked in four files in the build/ folder. This made Xcode very slow, since it was checking the git status during compilation all the time. Still, Xcode 4 is much slower than Xcode 3 after this. So I also upgraded our machines to have at least 8 GB of RAM. This was definitely much of an improvement. It seems that development machines using Xcode 4 should have 8 GB RAM minimum. The more, the better…

LaTeX formulas in gnuplot

As a reminder to myself: On the TeX Stackexchange, there is a nice question and discussion by me and some helpful people on how to use LaTeX code in gnuplot / how to embed LaTeX equations in a plot. A copy of my revised answer:

First, we set up a gnuplot called test.plt:

plot [-5:5] [-1.5:1.5] sin(x+pi) title "$\sin(x+\pi)$"

Then we also set up a small Makefile:

.SUFFIXES: .plt .tex .pdf



%.tex: %.plt

gnuplot -e " 

	set format '$%g$' ; 

	set terminal epslatex standalone color ; 

	set output '$@' 

	" $<



%.pdf: %.tex

	pdflatex $<



all: test.pdf

Running “make all” will produce this plot:

Emacs other-window backwards

I am currently writing a lot of text in Emacs, and I need to work on multiple files in parallel. So I use the split window functionality a lot. With C-x o you can switch to the next split window. However, it would be nice to go backward as well. The solution is simple, and is given on Stackoverflow and some other blogs:

(defun prev-window ()

  (interactive)

  (other-window -1))

(global-set-key (kbd "C-x p") 'prev-window)

Just put this in you init.el, and you can cycle backwards using C-x p.

SSL Everywhere for Safari

The EFF has published a Firefox extension to force HTTPS on as many websites as possible. This is a good idea(tm). But on OS X I use Safari, not Firefox. So I was wondering if there is a similar extension for Safari. It turns out there is. However, this extension is available in source only. The reason for this is given in a blog post by the developer. In short: The Safari extension API is limited, and the extension cannot guarantee that all your session cookies are transferred via HTTPS, making you vulnerable to stuff like Firesheep. And that is a bad thing(tm). But it is still useful, since it will redirect you to secure versions of the websites. One thing to note when following the build instructions: You need to enroll in the free Safari Dev program, and get a developer certificate. This is very well described over at Apple’s developer center. After that, you can enable the developer menu in Safari’s settings and just install the extension from the cloned git repository.

What are the best Web Galleries?

I am one of the few avid MobileMe users. I use the gallery and like it. Nice upload features, integration into iPhoto. Not perfect, but it does the work, plus I have lots of disk space. However, Apple makes the transition from MobileMe to iCloud. During this transition, several features of MobileMe will be dropped. Besides the very useful syncing of keychains between computers, the gallery will cease to function. Some strange photo stream service will be introduced, which does not seem to be a real gallery replacement, but more like a large cache of you last 1,000 pictures taken. Useful, but only to a limited extent. So what are my alternatives? I need (in order of importance):

  • Share with other people (who are not signed in, a la Facebook)
  • 5-10 GB space for pictures or more
  • Able to make photo albums, user gets a nice web browser based viewer
  • Option for users to download the photos
  • Optional high resolution versions of photos (2048 pixels or more)
  • Good integration with iPhone, iPhoto et al.
I would pay for that service, if it includes 10 GB space or more. 
I already found out that Flickr and Picasa Web offer unlimited space, but in the free version there are quite the restrictions (limited image resolution, image usage by hoster, limited number of photos that can be controlled, advertisements, …). Plus for example the Picasa Web Uploader for the Mac is horribly outdated (iPhoto ’08…?).
So what other options are there? Which one is the best?

Switching the active branch in a bare git repository

If you ever need to delete the “active” branch in a git repository, you need to first switch the active branch. Because you cannot delete the branch you are sitting on… You cannot checkout a branch, as you would usually do. You have to change the symbolic reference called HEAD. You can do this with the symbolic-ref command:

$ git branch
* deletethis
  somebranch
$ git symbolic-ref HEAD refs/heads/somebranch
$ git branch
  deletethis
* somebranch
$ git branch -d deletethis

Accessing the keychain in OS X from the command line

There is a very useful utility called security(1) in OS X, which lets you manipulate your keychain from the command line. You can easily im- and export keys and certificates using this. This is especially useful for AppStore developers, who code on multiple Macs. Having the signing keys in sync is kind of a challenging solution, if you don’t use keychain syncing via MobileMe. For example you can import a key like this into your login keychain:

$ security list-keychains
   "/Users/yourguy/Library/Keychains/login.keychain"
   "/Library/Keychains/System.keychain"
$ security import -k /Users/yourguy/Library/Keychains/login.keychain somekey.pem
1 key imported.

Hope this helps.