Eigen 入门 1 - Eigen简介

简介

Eigen是一个开源的矩阵和向量的计算库。其主要提供了

• 密集矩阵定义和计算
• 稀疏矩阵定义及计算
• 几何意义

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安装

Eigen其实并不用安装，应为其直接提供了C++的源码，而且是最有.h头文件，所有的声明和定义都在头文件内。

但这里说的安装，包括了源码拷贝到对应的系统位置，还有相关的一些设定。

Mac上简单安装

源码

如果你熟悉make操作或CMake，eigen并不需要安装，简单地下载并解压得到源码即可。实际上，在下载的Eigen子目录下的头文件是你唯一需要的，它们对所有的平台都是一致的，包括Windows，Linux，Mac……。然后你可以在你的c/C++代码中#include相关的头文件，然后编译运行。

mac 工具安装

在mac上可以使用Brew进行简单安装

$ brew info eigen
eigen: stable 3.3.7 (bottled), HEAD
C++ template library for linear algebra
https://eigen.tuxfamily.org/
Not installed
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/eigen.rb
==> Dependencies
Build: cmake ✘
==> Options
--HEAD
	Install HEAD version
$ 
$ $ brew install eigen --verbose
Updating Homebrew...

==> Downloading https://homebrew.bintray.com/bottles/eigen-3.3.7.high_sierra.bottle.tar.gz
==> Downloading from https://akamai.bintray.com/79/79c52d57394cf485eb324effab69279e4f3beb63cbacfa600ae0a678d852a827?__gda__=exp=1581844210~hmac=3a6b883979c10748ffa852494407055aaca620e8b30e0c97d7c7b8bd6851236d&response-content-disposition=attachment%3Bfilename%3D%22eigen-3.3.7.high_sierra.bottle.tar.gz%22&response-content-type=application%2Fgzip&requestInfo=U2FsdGVkX1-2mVVKrexc5neg1TrVW75s7zacghZ5TLvPZbLaz7dtUFwNXHsk8XEfLSru-n2zcqrHOlOeEegdJHNuwXt_XEfVbXexPTH51i_jVGnxk9JGEU5asLAv0floxQMpeumtk_R5vqAU-X55Aw&response-X-Checksum-Sha1=02b91fb73eecd067d7830bb7f394a02349893b8a&response-X-Checksum-Sha2=79c52d57394cf485eb324effab69279e4f3beb63cbacfa600ae0a678d852a827
/usr/bin/curl -q --globoff --show-error --user-agent Homebrew/2.2.5\ \(Macintosh\;\ Intel\ Mac\ OS\ X\ 10.13.6\)\ curl/7.54.0 --fail --location --remote-time --continue-at 0 --output /Users/david/Library/Caches/Homebrew/downloads/6f2e7171c37395b3cceb4bc7a13d60781e8dc55a1f4936f8ed4500d585bcef8e--eigen-3.3.7.high_sierra.bottle.tar.gz.incomplete https://akamai.bintray.com/79/79c52d57394cf485eb324effab69279e4f3beb63cbacfa600ae0a678d852a827\?__gda__=exp=1581844210\~hmac=3a6b883979c10748ffa852494407055aaca620e8b30e0c97d7c7b8bd6851236d\&response-content-disposition=attachment\%3Bfilename\%3D\%22eigen-3.3.7.high_sierra.bottle.tar.gz\%22\&response-content-type=application\%2Fgzip\&requestInfo=U2FsdGVkX1-2mVVKrexc5neg1TrVW75s7zacghZ5TLvPZbLaz7dtUFwNXHsk8XEfLSru-n2zcqrHOlOeEegdJHNuwXt_XEfVbXexPTH51i_jVGnxk9JGEU5asLAv0floxQMpeumtk_R5vqAU-X55Aw\&response-X-Checksum-Sha1=02b91fb73eecd067d7830bb7f394a02349893b8a\&response-X-Checksum-Sha2=79c52d57394cf485eb324effab69279e4f3beb63cbacfa600ae0a678d852a827
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 1121k  100 1121k    0     0  31338      0  0:00:36  0:00:36 --:--:-- 22652
==> Verifying 6f2e7171c37395b3cceb4bc7a13d60781e8dc55a1f4936f8ed4500d585bcef8e--eigen-3.3.7.high_sierra.bottle.tar.gz checksum
==> Pouring eigen-3.3.7.high_sierra.bottle.tar.gz
tar xof /Users/david/Library/Caches/Homebrew/downloads/6f2e7171c37395b3cceb4bc7a13d60781e8dc55a1f4936f8ed4500d585bcef8e--eigen-3.3.7.high_sierra.bottle.tar.gz -C /var/folders/b3/gb4zt5zs0y58mk5sq84grj4m0000gn/T/d20200216-2146-1nkw3yi
cp -pR /var/folders/b3/gb4zt5zs0y58mk5sq84grj4m0000gn/T/d20200216-2146-1nkw3yi/eigen/. /usr/local/Cellar/eigen
chmod -Rf +w /var/folders/b3/gb4zt5zs0y58mk5sq84grj4m0000gn/T/d20200216-2146-1nkw3yi
==> Finishing up
ln -s ../Cellar/eigen/3.3.7/include/eigen3 eigen3
rm /usr/local/share/cmake
mkdir -p /usr/local/share/cmake/Help
mkdir -p /usr/local/share/cmake/Help/command
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ln -s ../../../../Cellar/cmake/3.13.4/share/cmake/Help/command/ctest_run_script.rst ctest_run_script.rst
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