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   _       _ _(_)_     |
  (_)     | (_) (_)    |   A fresh approach to technical computing
   _ _   _| |_  __ _   |
  | | | | | | |/ _` |  |           http://julialang.org
  | | |_| | | | (_| |  |       [email protected]
 _/ |\__'_|_|_|\__'_|  |
|__/                   |

## The Julia Language

Julia is a high-level, high-performance dynamic language for technical computing. The main homepage for Julia can be found at julialang.org. This is the GitHub repository of Julia source code, including instructions for compiling and installing Julia, below.

• Homepage: http://julialang.org
• Discussion: http://groups.google.com/group/julia-dev/
• Source code: https://github.com/JuliaLang/julia
• Git clone URL: git://github.com/JuliaLang/julia.git
• Documentation: https://github.com/JuliaLang/julia/wiki

## Supported Platforms

• GNU/Linux: x86/64 (64-bit); x86 (32-bit).
• Darwin/OS X: x86/64 (64-bit)

## Source Download & Compilation

First, acquire the source code either by cloning the git repository (requires git to be installed):

git clone git://github.com/JuliaLang/julia.git

or, if you don't have git installed, by using wget and tar to fetch and unpack the source:

mkdir julia && wget -O - https://github.com/JuliaLang/julia/tarball/master | tar -zxf- -C julia --strip-components 1

Next, enter the julia/ directory and run make to build the julia executable. When compiled the first time, it will automatically download and build its external dependencies. This takes a while, but only has to be done once. Note: the build process will not work if any of the build directory's parent directories have spaces in their names (this is due to a limitation in GNU make).

Once it is built, you can either run the julia executable using its full path in the directory created above, or add that directory to your executable path so that you can run the julia program from anywhere:

export PATH="$(pwd)/julia:$PATH"

Now you should be able to run julia like this:

julia

If everything works correctly, you will see a Julia banner and an interactive prompt into which you can enter expressions for evaluation. You can read about getting started in the manual.

### Platform-Specific Notes

On some Linux distributions (for instance Ubuntu 11.10) you may need to change how the readline library is linked. If you get a build error involving readline, try changing the value of USE_SYSTEM_READLINE in Make.inc to 1.

On Ubuntu, you may also need to install the package libncurses5-dev.

If OpenBLAS fails to build in getarch_2nd.c, you need to specify the architecture of your processor in Make.inc.

On OS X, you may need to install gfortran. Either download and install gfortran.dmg, or install homebrew and run

brew install gfortran
ln -s /usr/local/bin/gfortran-4.2 /usr/local/bin/gfortran

## Required Build Tools & External Libraries

Julia depends on a number of mature, state-of-the art C and Fortran libraries. When installing from source, these libraries are automatically downloaded and compiled.

• GNU make — building dependencies.
• gcc, g++, gfortran — compiling and linking C, C++ and Fortran code.
• Perl — preprocessing of header files of libraries.
• wget — to automatically download external libraries:
  • LLVM — compiler infrastructure.
  • fdlibm — a portable implementation of much of the system-dependent libm math library's functionality.
  • MT — a fast Mersenne Twister pseudorandom number generator library.
  • OpenBLAS — a fast, open, and maintained basic linear algebra subprograms (BLAS) library, based on Kazushige Goto's famous GotoBLAS.
  • LAPACK — a library of linear algebra routines for solving systems of simultaneous linear equations, least-squares solutions of linear systems of equations, eigenvalue problems, and singular value problems.
  • SuiteSparse — a library of linear algebra routines for sparse matrices
  • ARPACK — a collection of subroutines designed to solve large, sparse eigenvalue problems.
  • FFTW — library for computing fast Fourier transforms very quickly and efficiently.
  • PCRE — Perl-compatible regular expressions library.
  • GNU readline — library allowing shell-like line editing in the terminal, with history and familiar key bindings.
  • D3 — JavaScript visualization library.

## Directories

attic/         old, now-unused code
contrib/       emacs and textmate support for julia
examples/      example julia programs
external/      external dependencies
j/             source code for julia's standard library
lib/           shared libraries loaded by julia's standard libraries
src/           source for julia language core
test/          unit and function tests for julia itself
ui/            source for various front ends

## Binary Installation

Because of the rapid pace of development at this point, we recommend installing the latest Julia from source, but platform-specific tarballs with containing pre-compiled binaries are also available for download:

• GNU/Linux x86: https://github.com/downloads/JuliaLang/julia/julia-77bdd202ec-Linux-i686.tar.gz
• GNU/Linux x86/64: https://github.com/downloads/JuliaLang/julia/julia-1fdd1e4e56-Linux-x86_64.tar.gz
• Darwin/OS X x86/64: https://github.com/downloads/JuliaLang/julia/julia-c4865bd18d-Darwin-i386.tar.gz

Download the appropriate tarball and untar it somewhere; for example, if you are on an OS X (Darwin) x86/64 system, do the following:

wget https://github.com/downloads/JuliaLang/julia/julia-c4865bd18d-Darwin-i386.tar.gz
tar zxvf julia-c4865bd18d-Darwin-i386.tar.gz

You can either run the julia executable using its full path in the directory created above, or add that directory to your executable path so that you can run the julia program from anywhere:

export PATH="$(pwd)/julia:$PATH"

Now you should be able to run julia like this:

julia

If everything works correctly, you will see a Julia banner and an interactive prompt into which you can enter expressions for evaluation. You can read about getting started in the manual.

## Editor & Terminal Setup

Julia support is currently available for Emacs, Vim, and TextMate. Support files and instructions for configuring these editors can be found in contrib/.

Adjusting your terminal bindings is optional; everything will work fine without these key bindings. For the best interactive session experience, however, make sure that your terminal emulator (Terminal, iTerm, xterm, etc.) sends the ^H sequence for Backspace (delete key) and that the Shift-Enter key combination sends a \n newline character to distinguish it from just pressing Enter, which sends a \r carriage return character. These bindings allow custom readline handlers to trap and correctly deal with these key sequences; other programs will continue behave normally with these bindings. The first binding makes backspacing through text in the interactive session behave more intuitively. The second binding allows Shift-Enter to insert a newline without evaluating the current expression, even when the current expression is complete. (Pressing an unmodified Enter inserts a newline if the current expression is incomplete, evaluates the expression if it is complete, or shows an error if the syntax is irrecoverably invalid.)

On Linux systems, the Shift-Enter binding can be set by placing the following line in the file .xmodmaprc in your home directory:

keysym Return = Return Linefeed