Sage: Open Source Mathematical Software

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

Copyright (C) 2005-2019 The Sage Development Team

https://www.sagemath.org

The Sage Library is GPLv2+, and included packages have compatible OSS licenses. Over 400 people have contributed code to Sage. In many cases, documentation for modules and functions list the authors.

Getting Started

If you downloaded a binary (i.e. a version of SageMath prepared for a specific operating system), Sage is ready to start -- just open a terminal in the directory where you extracted the binary archive and type:

./sage

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 or ask on ask.sagemath.org.

Contributing to Sage

If you'd like to contribute to Sage, be sure to read the Developer's Guide.

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.

Ports are in progress to some other, less common platforms. The list of supported platforms and their current statuses are given in our wiki.

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

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.

1. Make sure your system has an SSL library and its development files installed

   Like Python, on which it is based, Sage uses the OpenSSL library for added performance if made available by the operating system. It has been shown that Sage can be successfully built against other SSL libraries, with some of its features disabled.

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

   • All Linux versions: gcc, make, m4, perl, ranlib, git, and tar (a matching set of gcc, gfortran and g++ will avoid the compilation of Sage-specific compilers). It should also be possible to use clang/clang++, however this is less well-tested.

   • Fedora or RedHat systems: the perl-ExtUtils-MakeMaker package. (install these using your package manager)

   • OS X:

     • Make sure you have installed the most recent version of Xcode which you can install for free from the App Store.
     • You also need to install the "command line tools". When using OS X Mavericks, after installing Xcode, run xcode-select --install from a terminal window: 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. You might also have Homebrew or a similar "Apple's missing package manager" system installed, with and libraries such gfortran, gmp, etc installed. (However, this is still experimental as of May 2019).

   • Other platforms: See detailed instructions below.

3. It might be desirable, it terms of faster building and better portability, to install, as system packages, an ever increasing list of Sage packages which otherwise might have to be built. The following is a list of Sage packages "replaceable" by system's packages as of Sage release 8.8: bzip2, curl, cmake, gcc/clang, gf2x, gfortran (usually part of gcc installation), git, gmp, libffi, patch, pcre, perl_term_readline_gnu, xz/lzma, yasm, zeromq, zlib. Details and names of system packages containing these are system-dependent. E.g. on Debian bzip2 lives in libbz2-dev. More details on this are in Installation manual.

4. Extract the tarball

   tar zxvf sage-*.tar.gz
   

5. 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 described in more detail in the Installation Guide.

Implementation

Sage has significant components written in the following languages: C/C++, Python, Cython, Lisp, Fortran, and a bit of Perl. Lisp (ECL), Python, and Cython are built as part of Sage.

Docker Images

You can also have a look at our Docker images to run Sage. To use these images install Docker and follow the instructions on our Docker Hub page.

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: (a.k.a MacOS) Make sure you have a recent Xcode version. If you don't, go to https://developer.apple.com/, sign up, and download the free Xcode package. Usually, Xcode's command line tools suffice to build Sage, although several times new releases of Xcode broke this. Only OS X >= 10.4 is supported, and (as of May 2019) we only test Sage on OS X >= 10.6.

   • 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 our wiki (outdated as of May 2019).

   • Windows: Download and install VirtualBox, and then download the Sage virtual appliance.

   • 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 into a directory, making sure there are no spaces in the path to the resulting directory.

   Note that moving the directory after Sage has been built will require to build Sage again.

4. Change to the Sage directory using cd.

5. Optional: set some environment variables to customize the build.

   For example, the MAKE environment variable controls whether to run several jobs in parallel, while the SAGE_CHECK environment variable controls whether to perform more tests during the installation. For an in-depth discussion of environment variables for building Sage, see the installation guide.

   On a machine with 4 processors, say, typing export MAKE="make -j4" will configure the build script to perform a parallel compilation of Sage using 4 jobs. You might even consider -j5 or -j6, as building with more jobs than CPU cores can speed things up further. You might in addition pass a -l load 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 the make documentation.

   If you want to run the test suite for each individual Sage package as it gets installed, type export SAGE_CHECK="yes". This will run each test suite, raising an error if any failure occurs. Python's test suite has been disabled by default, because it causes failures on most systems. To enable the Python test suite, set the environment variable SAGE_CHECK_PACKAGES to python.

6. To start the build, type make.

   Note: to build a Python2-based Sage, instead of typing make, type

   make configure
   ./configure --with-python=2
   make
   

   This will build Sage based on Python 2 rather than based on Python 3, which is the default since sage 9.0.

7. 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).

8. Type ./sage to try it out.

9. Optional: Type make ptestlong 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/ptestlong.log that contains errors to the sage-support mailing list. If there are numerous failures, there was a serious problem with your build.

   Note: if you built for Python 3, you can instead run make ptest-python3.

10. The HTML version of the documentation is built during the compilation process of Sage and resides in the directory local/share/doc/sage/html/.

11. Optional: If you want to build the PDF version of the documentation, run make doc-pdf (this requires LaTeX to be installed).

12. Optional: You might install optional packages of interest to you: type ./sage --optional to get a list.

13. 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.

14. 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.

Troubleshooting

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 build/pkgs/. 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. However, it almost always better to use C, C++ and Fortran compilers already available on the system. To force using specific compilers, set environment variables CC, CXX, and FC (for C, C++, and Fortran compilers, respectively) to the desired values, and run ./configure. E.g. CC=clang CXX=clang++ FC=gfortran ./configure will configure Sage to be built with Clang C/C++ compilers and Fortran compiler gfortran.

It is determined automatically whether Sage's GCC package, or just its part containing Fortran compiler gfortran needs to be installed. This can be overwritten by running ./configure with option --without-system-gcc.

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 Sage tarball)
├── build
│   └── 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, docs
│       └── doc           Viewable docs of Sage and of some components
│   └── 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
├── m4                    M4 macros for configure
│   └── *.m4
├── Makefile              Running "make" uses this file
├── README.md             This file
├── sage                  Script to start Sage
├── src                   All of Sage source (not third-party packages)
│   ├── bin               Scripts that Sage uses internally
│   ├── doc               Sage documentation sources
│   └── 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 our Developer's Guide.

Build System

This is a brief summary of the Sage software distribution's build system. There are two components to the full Sage system--the Sage Python library and its associated user interfaces, and the larger software distribution of Sage's main dependencies (for those dependencies not supplied by the user's system).

Sage's Python library is built and installed using a setup.py script as is standard for Python packages (Sage's setup.py is non-trivial, but not unusual).

Most of the rest of the build system is concerned with building all of Sage's dependencies in the correct order in relation to each other. The dependencies included by Sage are referred to as SPKGs (i.e. "Sage Packages") and are listed under build/pkgs.

The main entrypoint to Sage's build system is the top-level Makefile at the root of the source tree. Unlike most normal projects that use autoconf (Sage does as well, as described below), this Makefile is not generated. Instead, it contains a few high-level targets and targets related to bootstrapping the system. Nonetheless, we still run make <target> from the root of the source tree--targets not explicitly defined in the top-level Makefile are passed through to another Makefile under build/make/Makefile.

The latter build/make/Makefile is generated by an autoconf-generated configure script, using the template in build/make/Makefile.in. This includes rules for building the Sage library itself (make sagelib), and for building and installing each of Sage's dependencies (e.g. make python2).

Although it's possible to manually run Sage's configure script if one wants to provide some customizations (e.g. it is possible to select which BLAS implementation to use), the top-level Makefile will run configure for you, in order to build build/make/Makefile since it's a prerequisite for most of Sage's make targets.

The configure script itself, if it is not already built, can be generated by running the bootstrap script (the latter requires GNU autotools being installed). The top-level Makefile also takes care of this automatically.

To summarize, running a command like make python3 at the top-level of the source tree goes something like this:

1. make python3
2. run ./bootstrap if configure does not exist
3. run ./configure if build/make/Makefile does not exist
4. cd into build/make and run the install script--this is little more than a front-end to running make -f build/make/Makefile python3, which sets some necessary environment variables and logs some information
5. build/make/Makefile contains the actual rule for building python3; this includes building all of python3's dependencies first (and their dependencies, recursively); the actual package installation is performed with the sage-spkg program

Relocation

It used to be possible to move the sage-x.y.z/ directory anywhere you want, however, this is no longer supported. 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 important that the path to Sage does not have any spaces and non-ASCII characters in it.

For a system-wide installation, you have to build Sage as a "normal" user and then as root you can change permissions. 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.

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
   

   The result is placed in the directory dist/.

2. To make a binary distribution with your currently installed packages, visit sagemath/binary-pkg.

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 COPYING.txt for more details.

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