【C++零散】c++调用matplotlib

参考资料

• c++调用matplotlib
• matplotlib-cpp

一、c++调用matplotlib

matplotlib-cpp项目地址在：https://github.com/lava/matplotlib-cpp，仓库内容很简单，核心的东西就是一个头文件matplotlibcpp.h， 这个头文件封装了大量了的C++调用matplotlib的api，使用的时候只要将matplotlibcpp.h复制到自己的项目中include就可以了。至于怎么使用，作者也给了比较详细的教程和资料，Readme和examples都有详细的使用方法，contrib里面则是介绍windows平台编译example的方法。

1 编译example

使用CMake编译matplotlib-cpp是比较方便的，作者也非常贴心地给出了CMakeLists.txt,也非常简单假如要编译自己地matplotlib-cpp项目，CMakeLists.txt只需要以下几行配置就可以了

find_package(Python3 COMPONENTS Development NumPy)
include_directories(main PRIVATE ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS})
target_link_libraries(main Python3::Python Python3::NumPy)

2 使用

#include "matplotlib-cpp/matplotlibcpp.h"
#include 

namespace plt = matplotlibcpp;

int main()
{
    // Prepare data.
    int n = 5000;
    std::vector<double> x(n), y(n), z(n), w(n,2);
    for(int i=0; i<n; ++i) {
        x.at(i) = i*i;
        y.at(i) = sin(2*M_PI*i/360.0);
        z.at(i) = log(i);
    }

    // Set the size of output image to 1200x780 pixels
    plt::figure_size(1200, 780);
    // Plot line from given x and y data. Color is selected automatically.
    plt::plot(x, y);
    // Plot a red dashed line from given x and y data.
    plt::plot(x, w,"r--");
    // Plot a line whose name will show up as "log(x)" in the legend.
    plt::named_plot("log(x)", x, z);
    // Set x-axis to interval [0,1000000]
    plt::xlim(0, 1000*1000);
    // Add graph title
    plt::title("Sample figure");
    // Enable legend.
    plt::legend();
    // Save the image (file format is determined by the extension)
    plt::save("./basic.png");
}

#include "matplotlib-cpp/matplotlibcpp.h"
#include 

namespace plt = matplotlibcpp;

int main()
{
    int n = 1000;
    std::vector<double> x, y, z;

    for (int i = 0; i < n; i++)
    {
        x.push_back(i * i);
        y.push_back(sin(2 * M_PI * i / 360.0));
        z.push_back(log(i));

        if (i % 10 == 0)
        {
            // Clear previous plot
            plt::clf();
            // Plot line from given x and y data. Color is selected automatically.
            plt::plot(x, y);
            // Plot a line whose name will show up as "log(x)" in the legend.
            plt::named_plot("log(x)", x, z);

            // Set x-axis to interval [0,1000000]
            plt::xlim(0, n * n);

            // Add graph title
            plt::title("Sample figure");
            // Enable legend.
            plt::legend();
            // Display plot continuously
            plt::pause(0.01);
        }
    }
}