Sage: Open Source Mathematical Software

       "Creating a Viable Open Source Alternative to
          Magma, Maple, Mathematica, and MATLAB"

    Copyright (C) 2005-2014 The Sage Development Team

        http://www.sagemath.org

The Sage Library is GPLv2+, included packages have compatible OSS
licenses (see COPYING.txt). Over 400 people have contributed code to
Sage. Please see the following web page for a list:

    http://www.sagemath.org/development-map.html

In many cases, documentation for modules and functions list the
authors.


GETTING STARTED
---------------

This README.txt contains build instructions for Sage. If you downloaded
a binary, you do not need to do anything; just execute:

    ./sage

from the command line. If you downloaded the sources, please read below
on how to build Sage and work around common issues.

If you have questions or encounter problems, please do not hesitate
to email the sage-support mailing list:

    http://groups.google.com/group/sage-support


SUPPORTED PLATFORMS
-------------------

Sage fully supports several Linux distributions, recent versions of
Mac OS X, Windows (using virtualization), as well as a number of
Solaris and OpenSolaris releases.

There should be no serious bugs in an officially released version of
Sage on any of the fully supported platforms, but any major issues with
a particular release will be documented on an errata page:

    http://wiki.sagemath.org/errata

Ports are in progress to some other, less common platforms. The list of
supported platforms and their current statuses are given at the
following web page:

    http://wiki.sagemath.org/SupportedPlatforms

If you are interested in helping port Sage to a new platform, please let
us know at the sage-devel mailing list:

    http://groups.google.com/group/sage-devel


QUICK INSTRUCTIONS TO BUILD FROM SOURCE
---------------------------------------

The following steps briefly outline the process of building Sage from
source. More detailed instructions, including how to build faster on
multicore machines, are contained later in this README and in the
Installation Guide:

    http://www.sagemath.org/doc/installation

1. Make sure you have the dependencies and 5 GB of free disk space.

   All Linux versions: gcc, make, m4, perl, ranlib, and tar.
   Fedora or RedHat systems: the perl-ExtUtils-MakeMaker package.
   (install these using your package manager)

   OS X: Xcode. Make sure you have installed the most recent version
   of Xcode. With recent versions of OS X (OS X Lion or later), you
   can install Xcode for free from the App Store. For pre-Lion
   versions of OS X, you can download Xcode from
   http://developer.apple.com/downloads/.

   With OS X, you also need to install the "command line tools". When
   using OS X Mavericks, after installing Xcode, run this command from
   a terminal window:

      xcode-select --install

   Then click "Install" in the pop-up window.

   When using OS X Mountain Lion or earlier, you need to install the
   command line tools from Xcode: run Xcode; then from the File
   menu, choose "Preferences", then the "Downloads" tab, and then
   "Install" the Command Line Tools.

   Other platforms: See detailed instructions below.

2. Extract the tarball:

       tar xvf sage-*.tar

3. cd into the Sage directory and type make:

       cd sage-*/
       make

   That's it! Everything is automatic and non-interactive. The build
   should work fine on all fully supported platforms. If it does not, we
   want to know!


ENVIRONMENT VARIABLES
---------------------

There are a lot of environment variables which control the install
process of Sage, see:

    http://sagemath.org/doc/installation/source.html#environment-variables


IMPLEMENTATION
--------------

Sage has significant components written in the following languages:
C/C++, Python, Cython, Lisp, and Fortran. Lisp (ECL), Python, and Cython
are built as part of Sage and a GNU Fortran (gfortran) binary is
included (OS X only), so you do not need them in order to build Sage.


MORE DETAILED INSTRUCTIONS TO BUILD FROM SOURCE
-----------------------------------------------

1. Make sure you have about 5 GB of free disk space.

2. Install build dependencies.

   Linux: See quick instructions above.

   OS X: Make sure you have XCode version >= 2.4, i.e. "gcc -v" should
   output build >= 5363. If you don't, go to:

       http://developer.apple.com/

   sign up, and download the free XCode package. Only OS X >= 10.4 is
   supported.

   Solaris and OpenSolaris: Building Sage on these platforms is more
   tricky than on Linux or OS X. For details on how to build Sage on
   these platforms, see:

       http://wiki.sagemath.org/solaris

   Windows: Download and install VirtualBox, and then download the
   Sage virtual appliance. For details, see:

       http://wiki.sagemath.org/SageAppliance

   NOTE: On some operating systems, it might be necessary to install
   gas/as, gld/ld, gnm/nm. On most platforms, these are automatically
   installed when you install the programs listed above.

3. Extract the Sage source tarball and cd into a directory with no
   spaces in it. If you have a machine with 4 processors, say, type
   the following to configure the build script to perform a parallel
   compilation of Sage using 4 jobs:

       export MAKE="make -j4"

   (With 4 processors, you might also consider "-j5" or "-j6" --
   building with more jobs than CPU cores can speed things up.)
   You might in addition pass a "-l" flag to "make": this
   sets a load limit, so for example if you execute

       export MAKE="make -j4 -l5.5"

   then "make" won't start more than one job at a time if the system
   load average is above 5.5.  See
   http://www.gnu.org/software/make/manual/make.html#Options-Summary
   and http://www.gnu.org/software/make/manual/make.html#Parallel.

   If you want to run the test suite for each individual spkg as it is
   installed, type:

       export SAGE_CHECK="yes"

   before starting the Sage build. This will run each test suite and
   will raise an error if any failures occur. Python's test suite has
   been disabled by default, because it causes failures on most
   systems. To renable the Python testsuite, set the environment
   variable SAGE_CHECK_PACKAGES to "python".

   To start the build, type:

       make

4. Wait about 20 minutes to 14 days, depending on your computer (it took
   about 2 weeks to build Sage on the T-Mobile G1 Android cell phone).

5. Type "./sage" to try it out.

6. OPTIONAL: Type "make ptest" to test all examples in the documentation
   (over 200,000 lines of input!) -- this takes from 10 minutes to
   several hours. Don't get too disturbed if there are 2 to 3 failures,
   but always feel free to email the section of logs/ptest.log that
   contains errors to the sage-support mailing list. If there are
   numerous failures, there was a serious problem with your build.

7. The HTML version of the documentation is built
   during the compilation process of Sage and resides in the directory:

       $SAGE_ROOT/src/doc/output/html/

   OPTIONAL: If you want to build the PDF version (requires LaTeX) of
   the documentation, run:

       make doc-pdf

8. OPTIONAL: It is highly recommended that you install the optional GAP
   database by typing:

       ./sage --optional

   then installing (with "./sage -i") the package whose name begins with
   database_gap. This will download the package from
   sage.math.washington.edu and install it. While you're at it, you
   might install other databases of interest to you.

9. OPTIONAL: It is recommended that you have both LaTeX and the
   ImageMagick tools (e.g. the "convert" command) installed since some
   plotting functionality benefits from it.

10. OPTIONAL: Read this if you are intending to run a Sage notebook
    server for multiple users. For security (i.e., to run
    "notebook(secure=True)") you want to access the server using the
    HTTPS protocol. First, install OpenSSL and the OpenSSL development
    headers on your system if they are not already installed. Then
    install pyOpenSSL by building Sage and then typing

        ./sage -i pyopenssl

    Note that this command requires internet access.  Alternatively,
    "make ssl" builds Sage and installs pyOpenSSL.


PROBLEMS
--------

If you have problems building Sage, check the Sage Installation Guide,
and also note the following.  Each separate component of Sage is
contained in an spkg; these are stored in spkg/standard/.  As each one
is built, a build log is stored in logs/pkgs/, so you can browse these
to find error messages.  If an spkg fails to build, the whole build
process will stop soon after, so check the most recent log files
first, or run

   grep -li "^Error" logs/pkgs/*

from the top-level Sage directory to find log files with error
messages in them.  Send (a small part of) the relevant log file to the
sage-devel mailing list, making sure to include at least some of the
error messages; probably someone there will have some helpful
suggestions.


SUPPORTED COMPILERS
-------------------

Sage includes a GCC (GNU Compiler Collection) package. In order to
build Sage, you need a C compiler which can build GCC and its
prerequisites. gcc version 4.0.1 or later should probably work. On
Solaris or OpenSolaris, building with the Sun compiler should also work.

The GCC package in Sage is not always installed. It is determined
automatically whether it needs to be installed. You can override this
by setting the environment variable SAGE_INSTALL_GCC=yes (to force
installation of GCC) or SAGE_INSTALL_GCC=no (to disable installation of
GCC). If you don't want to install GCC, you need to have recent
versions of gcc, g++ and gfortran; moreover, the versions must be equal.

There are some known problems with old assemblers, in particular when
building the ECM package. You should ensure that your assembler
understands all instructions for your processor. On Linux, this means
you need a recent version of binutils; on OS X you need a recent version
of XCode.


DIRECTORY LAYOUT
----------------

Simplified directory layout (only essential files/directories):

SAGE_ROOT                 Root directory (sage-x.y.z in the Sage tarball)
+-- build
|   +-- deps              Dependency information of packages
|   +-- pkgs              Every package is a subdirectory here
|       +-- atlas
|       ...
|       +-- zn_poly
+-- COPYING.txt           Copyright information
+-- local                 Compiled packages are installed here
|   +-- bin               Executables
|   +-- include           C/C++ headers
|   +-- lib               Shared libraries
|   +-- share             Databases, architecture-independent data
|   +-- var
|       +-- sage          List of installed packages
|       +-- tmp           Temporary files when building Sage
+-- logs 
|   +-- dochtml.log       Log of the documentation build
|   +-- install.log       Full install log
|   +-- pkgs              Build logs of individual packages
|       +--- atlas-3.10.1.p7.log
|       ...
|       +--- zn_poly-0.9.p11.log
+-- Makefile              Running "make" uses this file
+-- README.txt            This file
+-- sage                  Script to start Sage
+-- src                   All of the Sage source (not third-party packages)
|   +-- bin               Scripts that Sage uses internally
|   +-- doc               Sage documentation
|   +-- sage              The Sage library source code
+-- upstream              Source tarballs of packages
|   +-- atlas-3.10.1.tar.bz2
|   ...
|   +-- zn_poly-0.9.tar.bz2
+-- VERSION.txt

For more details, see:

    http://sagemath.org/doc/developer/coding_basics.html#files-and-directory-structure


RELOCATION
----------

You *should* be able to move the sage-x.y.z/ directory anywhere you
want. If you copy the sage script or make a symbolic link to it, you
should modify the script to reflect this (as instructed at the top of
the script). It is best if the path to Sage does not have any spaces in
it.

For a system-wide installation, as root you can move the sage-x.y.z/
directory to a system-wide directory. Afterwards, you need to start up
Sage as root at least once prior to using the system-wide Sage as a
normal user. See the Installation Guide for further information on
performing a system-wide installation:

    http://www.sagemath.org/doc/installation/source.html#installation-in-a-multiuser-environment

If you find anything that doesn't work correctly after you moved the
directory, please email the sage-support mailing list.


REDISTRIBUTION
--------------

Your local Sage install is almost exactly the same as any "developer"
install. You can make changes to documentation, source, etc., and very
easily package the complete results up for redistribution just like we
do.

1. To make your own source tarball of Sage, type:

       sage --sdist

2. To make a binary distribution with your currently installed packages,
   type:

       sage --bdist

3. To make a binary that will run on the widest range of target
   machines, set the SAGE_FAT_BINARY environment variable to "yes"
   before building Sage:

       export SAGE_FAT_BINARY="yes"
       make distclean && make
       ./sage --bdist

In all cases, the result is placed in the directory "$SAGE_ROOT/dist/".


CHANGES TO INCLUDED SOFTWARE
----------------------------

All software included with Sage is copyrighted by the respective authors
and released under an open source license that is "GPL version 3 or
later" compatible. See the file COPYING.txt for more details.

Sources are in unmodified (as far as possible) tarballs in the
"$SAGE_ROOT/upstream" directory. The remaining description, version
information, patches, and build scripts are in the accompanying
"$SAGE_ROOT/build/pkgs/<packagename>" directory. This directory is
part of the Sage git repository.