如何检查NumPy和SciPy中的BLAS/LAPACK链接？

Question

我正在搭建一个基于blas和lapack的numpy/scipy环境，差不多是按照这个教程来做的。

完成后，我该怎么检查我的numpy/scipy函数是否真的在使用我之前搭建的blas/lapack功能呢？

Answer 1

你可以使用链接加载器依赖工具来查看你构建中的C级钩子组件，看看它们是否依赖于你选择的blas和lapack库。我现在没有在Linux电脑旁边，但在OS X机器上，你可以在存放安装包的site-packages目录里进行这个操作：

$ otool -L numpy/core/_dotblas.so 
numpy/core/_dotblas.so:
    /System/Library/Frameworks/Accelerate.framework/Versions/A/Accelerate (compatibility version 1.0.0, current version 4.0.0)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 125.2.0)
    /System/Library/Frameworks/vecLib.framework/Versions/A/vecLib (compatibility version 1.0.0, current version 268.0.1)

$ otool -L scipy/linalg/flapack.so 
scipy/linalg/flapack.so (architecture i386):
    /System/Library/Frameworks/Accelerate.framework/Versions/A/Accelerate (compatibility version 1.0.0, current version 4.0.0)
    /usr/local/lib/libgcc_s.1.dylib (compatibility version 1.0.0, current version 1.0.0)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 111.1.4)
    /System/Library/Frameworks/vecLib.framework/Versions/A/vecLib (compatibility version 1.0.0, current version 242.0.0)
scipy/linalg/flapack.so (architecture ppc):
    /System/Library/Frameworks/Accelerate.framework/Versions/A/Accelerate (compatibility version 1.0.0, current version 4.0.0)
    /usr/local/lib/libgcc_s.1.dylib (compatibility version 1.0.0, current version 1.0.0)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 111.1.4)

$ otool -L scipy/linalg/fblas.so 
scipy/linalg/fblas.so (architecture i386):
    /System/Library/Frameworks/Accelerate.framework/Versions/A/Accelerate (compatibility version 1.0.0, current version 4.0.0)
    /usr/local/lib/libgcc_s.1.dylib (compatibility version 1.0.0, current version 1.0.0)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 111.1.4)
    /System/Library/Frameworks/vecLib.framework/Versions/A/vecLib (compatibility version 1.0.0, current version 242.0.0)
scipy/linalg/fblas.so (architecture ppc):
    /System/Library/Frameworks/Accelerate.framework/Versions/A/Accelerate (compatibility version 1.0.0, current version 4.0.0)
    /usr/local/lib/libgcc_s.1.dylib (compatibility version 1.0.0, current version 1.0.0)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 111.1.4)

在GNU/Linux系统上，把otool换成ldd，你就能得到你需要的答案。

Answer 2

你要找的内容是这个：

系统信息

我用atlas编译了numpy和scipy，你可以用下面的命令来检查：

import numpy.distutils.system_info as sysinfo
sysinfo.get_info('atlas')

查看文档可以找到更多命令。

Answer 3

这个方法 numpy.show_config()（或者 numpy.__config__.show()）可以显示一些在构建时收集到的链接信息。我的输出结果是这样的。我觉得这意味着我正在使用随 Mac OS 一起提供的 BLAS/LAPACK 库。

>>> import numpy as np
>>> np.show_config()

lapack_opt_info:
    extra_link_args = ['-Wl,-framework', '-Wl,Accelerate']
    extra_compile_args = ['-msse3']
    define_macros = [('NO_ATLAS_INFO', 3)]
blas_opt_info:
    extra_link_args = ['-Wl,-framework', '-Wl,Accelerate']
    extra_compile_args = ['-msse3', '-I/System/Library/Frameworks/vecLib.framework/Headers']
    define_macros = [('NO_ATLAS_INFO', 3)]