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@ -7,7 +7,7 @@ Spintrum creates an interface between a high-performance and low-level language
##Installation
Spintrum is supported only on Linux/Unix systems, and is primarily tested on Debian. For explanation, look at the FAQ below. If you'd like to compile Spintrum on operating systems other than debian, your efforts to do it will be minimal.
Spintrum is supported only on Linux/Unix systems, and is primarily tested on Debian. For explanation, look at the FAQ below. If you'd like to compile Spintrum on operating systems other than Debian, your efforts to do it will be minimal.
#####Prerequisites
- Linux/Unix (preferably Debian)
@ -19,40 +19,38 @@ Spintrum is supported only on Linux/Unix systems, and is primarily tested on Deb
#####In Python, the following libraries are required
- numpy
- scipy
- mpmath
- matplotlib
#####Do I need to compile OpenBLAS?
This depends on the performance you're trying to achieve. OpenBLAS, when compiled, creates binaries that are processor-specific, in order to achieve the best possible performance. In order to exploit this feature, it's recommended that you compile OpenBLAS.
Don't panic, as you don't have to do this yourself from scratch. The script `get_openblas.sh` should do this for you. It clones the OpenBLAS repository, and changes the optimization level of the compiler settings, and does the compilation. Run it using `sh get_openblas.sh`.
#####What optimization level should I take for OpenBLAS?
The default optimization level for OpenBLAS is `-O2`, which is fair. The script `get_openblas.sh` changes all optimization flags by default to `-Ofast`. This is an extreme exaggeration, and may cause [problems](http://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html). I recommend using O2 for tests, and going to Ofast once everything is prepared. Please read [the link](http://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html) that explains what these optimization flags mean. Then, edit the file `set_openblas_optimization.py`, and change the variable `target_optimization` to the desired optimization level.
#####What if I don't want to compile OpenBLAS?
The compilation script in the directory Spintrum expects a compiled version of OpenBLAS, either in the default directory that the script `get_openblas.sh` downloads and installs to, or an installed version of OpenBLAS in the operating system. Keep in mind that the default OpenBLAS in the Linux operating systems are not generally optimized for your processor.
The installer automatically installs OpenBLAS for you. If you would not like to have OpenBLAS compiled for you, then use the `Makefile` script through calling `make`, which will ask whether you want to have OpenBLAS compiled for you. Then, you're free to use the directory `spintrum` independently as a package, or copy it yourself to your Python installation. You have to have OpenBLAS installed on your system to have this work; otherwise, the compilation will fail.
#####Do I need Polymath?
Definitely! Polymath is a C++ interface to BLAS. It was also written by Spintrum team to separate the Maths library from the programming. Use the script `get_polymath.sh` to clone Polymath.
Definitely! Polymath is a C++ interface to BLAS. It was also written by the Spintrum team to separate the Maths library from the programming. The installer will get Polymath for you automatically from its repository.
#####How to install?
In the directory `Spintrum`, there's a `Makefile` that will do everything for you. Simply run the command `make` in that directory, and then if everything runs correctly, and no error messages are issued, run `make install` as root/superuser to install spintrum on your Python installation.
There are two ways:
- Use `pip` to do the installation for you with the command:
```sh
# pip3 install git+https://git.afach.de/samerafach/Spintrum
```
Note: The `#` means that these commands have to be executed as root. Don't literally type that `#` in the terminal. This will install dependencies for you, too.
- Or, you can use Spintrum as an independent package, by cloning the repository `https://git.afach.de/samerafach/Spintrum` yourself, and running `make`.
#####How to install missing prerequisites on Debian?
Simply run the following in the terminal (as superuser/root):
```sh
# apt-get install build-essential cmake g++ gcc python3
# pip3 install numpy scipy mpmath matplotlib
# apt-get install build-essential cmake g++ gcc gfortran python3 python3-pip
```
Note: The `#` means that these commands have to be executed as root. Don't literally type that `#` in the terminal.
#####Testing whether it works
After a successful installation, simply try the examples in the `examples` directory. They should all work, assuming you have
After a successful installation, simply try the examples in the `examples` directory. They should all work, assuming you have everything installed correctly. The dependencies of the examples are different than Spintrum itself. For example, the examples use Matplotlib, which plots signals and spectra. You have to install this yourself. On Debian, you can `sudo apt-get install python3-matplotlib` to do that. Also for fitting scripts, the package `scipy` is used, which you can install using `sudo pip3 install scipy`.
#####Caveat about Jupyter
@ -61,5 +59,5 @@ Spintrum works fine on Jupyter, except that the `stdout` and `stderr` output can
##FAQ
- **Q:** Why is spintrum not supported on Windows?
- **A:** Ignoring that Windows is way slower than Linux for calculations; Spintrum uses the well-known high-performance linear algebra library OpenBLAS. And since Python 3.5+ is compiled on Visual Studio 2015, and since Spintrum uses ctypes, which is the shared-library interface of Python, binary compatibility has to be achieved between Python and the compiled Spintrum library. On the other hand, OpenBLAS does not support compilation on Visual Studio with 64-bit (it supports only 32-bit), meaning that only small spin systems will be properly supported, since memory of 4+ GB cannot be used, which is not worth the effort, as too many changes have to be done to make Spintrum compatible with Windows. In the worst case, use a VMWare Workstation on your Windows Machine, and you'll get the best performance.
- **A:** Ignoring that Windows is way slower than Linux for calculations; Spintrum uses the well-known high-performance linear algebra library OpenBLAS. And since Python 3.5+ is compiled on Visual Studio 2015, and since Spintrum uses ctypes, which is the shared-library interface of Python, binary compatibility has to be achieved between Python and the compiled Spintrum library. On the other hand, OpenBLAS does not support compilation on Visual Studio with 64-bit (it supports only 32-bit), meaning that only small spin systems will be properly supported, since memory of 4+ GB cannot be used, which is not worth the effort, as too many changes have to be done to make Spintrum compatible with Windows. In the worst case, use a VMWare Workstation Virtual Machine on your Windows Machine, and you'll get the best performance.