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Python SciPy是否需要BLAS？

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问题：Python SciPy是否需要BLAS？
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问题：Python SciPy是否需要BLAS？

numpy.distutils.system_info.BlasNotFoundError: 
    Blas (http://www.netlib.org/blas/) libraries not found.
    Directories to search for the libraries can be specified in the
    numpy/distutils/site.cfg file (section [blas]) or by setting
    the BLAS environment variable.

我需要从该站点下载哪个tar？

我已经尝试过fortrans，但是一直出现此错误（明显地设置了环境变量之后）。

点击查看英文原文 
numpy.distutils.system_info.BlasNotFoundError: 
    Blas (http://www.netlib.org/blas/) libraries not found.
    Directories to search for the libraries can be specified in the
    numpy/distutils/site.cfg file (section [blas]) or by setting
    the BLAS environment variable.

Which tar do I need to download off this site?

I’ve tried the fortrans, but I keep getting this error (after setting the environment variable obviously).

回答 0

该SciPy的网页用来提供构建和安装说明，但说明现在依靠操作系统二进制分发。要在没有预编译所需库软件包的操作系统上构建SciPy（和NumPy），必须先构建然后静态链接到Fortran库BLAS和LAPACK：

mkdir -p ~/src/
cd ~/src/
wget http://www.netlib.org/blas/blas.tgz
tar xzf blas.tgz
cd BLAS-*

## NOTE: The selected Fortran compiler must be consistent for BLAS, LAPACK, NumPy, and SciPy.
## For GNU compiler on 32-bit systems:
#g77 -O2 -fno-second-underscore -c *.f                     # with g77
#gfortran -O2 -std=legacy -fno-second-underscore -c *.f    # with gfortran
## OR for GNU compiler on 64-bit systems:
#g77 -O3 -m64 -fno-second-underscore -fPIC -c *.f                     # with g77
gfortran -O3 -std=legacy -m64 -fno-second-underscore -fPIC -c *.f    # with gfortran
## OR for Intel compiler:
#ifort -FI -w90 -w95 -cm -O3 -unroll -c *.f

# Continue below irrespective of compiler:
ar r libfblas.a *.o
ranlib libfblas.a
rm -rf *.o
export BLAS=~/src/BLAS-*/libfblas.a

仅执行五个g77 / gfortran / ifort命令之一。我已注释掉所有内容，但我使用的是gfortran。随后的LAPACK安装需要一个Fortran 90编译器，并且由于两个安装都应使用相同的Fortran编译器，因此g77不应用于BLAS。

接下来，您需要安装LAPACK东西。SciPy网页的说明在这里也对我有所帮助，但我必须对其进行修改以适合我的环境：

mkdir -p ~/src
cd ~/src/
wget http://www.netlib.org/lapack/lapack.tgz
tar xzf lapack.tgz
cd lapack-*/
cp INSTALL/make.inc.gfortran make.inc          # On Linux with lapack-3.2.1 or newer
make lapacklib
make clean
export LAPACK=~/src/lapack-*/liblapack.a

2015年9月3日更新：今天验证了一些评论（感谢所有）：运行之前，make lapacklib编辑make.inc文件-fPIC并向OPTS和NOOPT设置添加选项。如果您使用的是64位体系结构或要编译为64位体系结构，请同时添加-m64。重要的是，在将这些选项设置为相同值的情况下编译BLAS和LAPACK。如果您忘记了，-fPICSciPy实际上会给您有关符号丢失的错误，并建议您使用此开关。make.inc我的设置中的特定部分如下所示：

FORTRAN  = gfortran 
OPTS     = -O2 -frecursive -fPIC -m64
DRVOPTS  = $(OPTS)
NOOPT    = -O0 -frecursive -fPIC -m64
LOADER   = gfortran

在旧机器（例如RedHat 5）上，gfortran可能安装在旧版本（例如4.1.2）中，并且不理解option -frecursive。make.inc在这种情况下，只需将其从文件中删除即可。

Makefile的lapack测试目标在我的设置中失败，因为它找不到blas库。如果您周全，则可以将blas库临时移至指定位置以测试lapack。我是一个懒惰的人，所以我相信开发人员可以使其工作并仅在SciPy中进行验证。

点击查看英文原文

The SciPy webpage used to provide build and installation instructions, but the instructions there now rely on OS binary distributions. To build SciPy (and NumPy) on operating systems without precompiled packages of the required libraries, you must build and then statically link to the Fortran libraries BLAS and LAPACK:

mkdir -p ~/src/
cd ~/src/
wget http://www.netlib.org/blas/blas.tgz
tar xzf blas.tgz
cd BLAS-*

## NOTE: The selected Fortran compiler must be consistent for BLAS, LAPACK, NumPy, and SciPy.
## For GNU compiler on 32-bit systems:
#g77 -O2 -fno-second-underscore -c *.f                     # with g77
#gfortran -O2 -std=legacy -fno-second-underscore -c *.f    # with gfortran
## OR for GNU compiler on 64-bit systems:
#g77 -O3 -m64 -fno-second-underscore -fPIC -c *.f                     # with g77
gfortran -O3 -std=legacy -m64 -fno-second-underscore -fPIC -c *.f    # with gfortran
## OR for Intel compiler:
#ifort -FI -w90 -w95 -cm -O3 -unroll -c *.f

# Continue below irrespective of compiler:
ar r libfblas.a *.o
ranlib libfblas.a
rm -rf *.o
export BLAS=~/src/BLAS-*/libfblas.a

Execute only one of the five g77/gfortran/ifort commands. I have commented out all, but the gfortran which I use. The subsequent LAPACK installation requires a Fortran 90 compiler, and since both installs should use the same Fortran compiler, g77 should not be used for BLAS.

Next, you’ll need to install the LAPACK stuff. The SciPy webpage’s instructions helped me here as well, but I had to modify them to suit my environment:

mkdir -p ~/src
cd ~/src/
wget http://www.netlib.org/lapack/lapack.tgz
tar xzf lapack.tgz
cd lapack-*/
cp INSTALL/make.inc.gfortran make.inc          # On Linux with lapack-3.2.1 or newer
make lapacklib
make clean
export LAPACK=~/src/lapack-*/liblapack.a

Update on 3-Sep-2015: Verified some comments today (thanks to all): Before running make lapacklib edit the make.inc file and add -fPIC option to OPTS and NOOPT settings. If you are on a 64bit architecture or want to compile for one, also add -m64. It is important that BLAS and LAPACK are compiled with these options set to the same values. If you forget the -fPIC SciPy will actually give you an error about missing symbols and will recommend this switch. The specific section of make.inc looks like this in my setup:

FORTRAN  = gfortran 
OPTS     = -O2 -frecursive -fPIC -m64
DRVOPTS  = $(OPTS)
NOOPT    = -O0 -frecursive -fPIC -m64
LOADER   = gfortran

On old machines (e.g. RedHat 5), gfortran might be installed in an older version (e.g. 4.1.2) and does not understand option -frecursive. Simply remove it from the make.inc file in such cases.

The lapack test target of the Makefile fails in my setup because it cannot find the blas libraries. If you are thorough you can temporarily move the blas library to the specified location to test the lapack. I’m a lazy person, so I trust the devs to have it working and verify only in SciPy.

回答 1

如果您需要使用最新版本的SciPy而非打包的版本，而无需经历构建BLAS和LAPACK的麻烦，则可以按照以下过程进行操作。

从存储库安装线性代数库（对于Ubuntu），

sudo apt-get install gfortran libopenblas-dev liblapack-dev

然后安装SciPy（在下载SciPy源代码之后）：python setup.py install或

pip install scipy

视情况可以是。

点击查看英文原文

If you need to use the latest versions of SciPy rather than the packaged version, without going through the hassle of building BLAS and LAPACK, you can follow the below procedure.

Install linear algebra libraries from repository (for Ubuntu),

sudo apt-get install gfortran libopenblas-dev liblapack-dev

Then install SciPy, (after downloading the SciPy source): python setup.py install or

pip install scipy

As the case may be.

回答 2

在Fedora上，这有效： 

 yum install lapack lapack-devel blas blas-devel
 pip install numpy
 pip install scipy

请记住除了安装“ blas ”和“ lapack ”之外，还要安装“ lapack-devel ”和“ blas-devel ”，否则，您将得到所提到的错误或“ numpy.distutils.system_info。LapackNotFoundError ”错误。

点击查看英文原文

On Fedora, this works: 

 yum install lapack lapack-devel blas blas-devel
 pip install numpy
 pip install scipy

Remember to install ‘lapack-devel‘ and ‘blas-devel‘ in addition to ‘blas’ and ‘lapack’ otherwise you’ll get the error you mentioned or the “numpy.distutils.system_info.LapackNotFoundError” error.

回答 3

我猜您在谈论在Ubuntu中进行安装。只需使用：

apt-get install python-numpy python-scipy

那也应该照顾BLAS库的编译。否则，编译BLAS库非常困难。

点击查看英文原文

I guess you are talking about installation in Ubuntu. Just use: 

apt-get install python-numpy python-scipy

That should take care of the BLAS libraries compiling as well. Else, compiling the BLAS libraries is very difficult.

回答 4

对于Windows用户，Chris提供了一个不错的二进制程序包（警告：下载量很大，为191 MB）：

点击查看英文原文

For Windows users there is a nice binary package by Chris (warning: it’s a pretty large download, 191 MB):

回答 5

遵循“ cfi”给出的说明对我有用，尽管它们遗漏了一些您可能需要的部分：

1）解压缩后的lapack目录可能称为lapack-XY（某些版本号），因此您可以将其重命名为LAPACK。 

cd ~/src
mv lapack-[tab] LAPACK

2）在该目录中，您可能需要执行以下操作：

cd ~/src/LAPACK 
cp lapack_LINUX.a libflapack.a
点击查看英文原文

Following the instructions given by ‘cfi’ works for me, although there are a few pieces they left out that you might need:

1) Your lapack directory, after unzipping, may be called lapack-X-Y (some version number), so you can just rename that to LAPACK. 

cd ~/src
mv lapack-[tab] LAPACK

2) In that directory, you may need to do:

cd ~/src/LAPACK 
cp lapack_LINUX.a libflapack.a

回答 6

尝试使用 

sudo apt-get install python3-scipy
点击查看英文原文

Try using 

sudo apt-get install python3-scipy