qixianyu-buaa/eigenchinesedocument

This is my translation of Chinese document of Eigen

eigenchinesedocument's Issues

编译错误问题

Subject

编译时存在未声明的变量，错误信息如下：

In file included from /home/wtc/Project/EigenChineseDocument/Eigen/chapter3_test.cpp:1:
~/Project/EigenChineseDocument/Eigen/Chapter3_SparseLinearAlgebra/Section1_SparseMatrixManipulations.hpp: In function ‘void Chapter3_SparseLinearAlgebra::Section1_SparseMatrixManipulations::TheSparseMatrixClass()’:
~Project/EigenChineseDocument/Eigen/Chapter3_SparseLinearAlgebra/Section1_SparseMatrixManipulations.hpp:133:42: error: ‘rows’ was not declared in this scope
  133 |                 SparseMatrix<double> mat(rows, cols);
      |                                          ^~~~
~/Project/EigenChineseDocument/Eigen/Chapter3_SparseLinearAlgebra/Section1_SparseMatrixManipulations.hpp:133:48: error: ‘cols’ was not declared in this scope; did you mean ‘cosl’?
  133 |                 SparseMatrix<double> mat(rows, cols);
      |                                                ^~~~
      |                                                cosl
make[2]: *** [CMakeFiles/chapter3_test.dir/build.make:76: CMakeFiles/chapter3_test.dir/chapter3_test.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:113: CMakeFiles/chapter3_test.dir/all] Error 2
make: *** [Makefile:84: all] Error 2

看起来是文档中的伪代码部分被错误地复制为了可运行的代码部分。我稍后会提一个PR解决这个问题。

我的环境

• Ubuntu 20.04
• Eigen 3.3.7

请问下Section3_MatrixFreeSolvers.hpp中MatrixFree是什么意思？

看了官方教程，cg slover可以是matrix-free，但是没明白这是什么意思，是要自己构造一个class而不同eigen官方的matrix？