Is this m1 architecture issue?

[yoonsik-jung-opt]

I just try to run the example codes below.

#include <random>

int main() {
    using namespace matplot;

    auto x = linspace(0, 3 * pi, 200);
//    auto y = transform(x, [&](double x) { return cos(x) + rand(0, 1); });

//    scatter(x, y);

//    show();
    return 0;
}

After run the code on CLion, I got the error message. I installed the matplot++ using brew and link to my project.
I guess my chip architecture of macbook causes the error, but I am not sure. (I am newbie on c++) .

There are logmsg and cmakelist.txt that I used.
Thanks.

cmake_minimum_required(VERSION 3.21)
project(LADMH)
set(CMAKE_CXX_STANDARD 14)
set(Matplot++_DIR "")
include_directories(/usr/local)
find_package(Matplot++ REQUIRED)

if (Matplot++_FOUND)
    add_executable(LADMH main.cpp preprocessing.h pattern_generation.h utilities.h)
    target_link_libraries(LADMH PUBLIC Matplot++::matplot)
endif ()

Output

[1/1] Linking CXX executable LADMH
FAILED: LADMH 
: && /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ -g -arch arm64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.3.sdk -Wl,-search_paths_first -Wl,-headerpad_max_install_names  CMakeFiles/LADMH.dir/main.cpp.o -o LADMH  -Wl,-rpath,/usr/local/lib  /usr/local/lib/libmatplot.dylib && :
ld: warning: ignoring file /usr/local/lib/libmatplot.dylib, building for macOS-arm64 but attempting to link with file built for macOS-x86_64
Undefined symbols for architecture arm64:
  "matplot::linspace(double, double, unsigned long)", referenced from:
      _main in main.cpp.o
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
ninja: build stopped: subcommand failed.

Steps to Reproduce

# Your steps go here
/Applications/CLion.app/Contents/bin/cmake/mac/bin/cmake --build /Users/myname/Desktop/workspace/PRJNAME/cmake-build-debug --target PRJNAME

Platform

• cross-platform issue - linux
• cross-platform issue - windows
• cross-platform issue - macos

Environment Details:

• OS: Monterey(Apple M1 Pro)
• OS Version: 12.3.1
• Compiler:clang
• Compiler version:12.0.5

Additional context

[alandefreitas]

In your example you have

#include <random>

but still need the matplot headers.

I don't know if the version from brew works OK on arm processors. You can always install from source though.

In your CMake, this

set(Matplot++_DIR "")

and this

include_directories(/usr/local)

are very unusual.

• The find_package script is supposed to set Matplot++_DIR for you.
• Nowadays we use target_include_directories instead of include_directories
• And there's no point in including the whole /usr/local/ directory, as you'll get the header files but not the complete library targets you need to link.

Also, if you have REQUIRED in your

find_package(Matplot++ REQUIRED)

then you don't need

if (Matplot++_FOUND)

because REQUIRED will already fail when Matplot++ is not found (when NOT Matplot++_FOUND).

Then your error is ignoring file /usr/local/lib/libmatplot.dylib because the library you installed is macOS-x86_64 and your computer is macOS-arm64. x86_64 is the version you get from the release section. I don't know what the brew recipe does here. But you can always 1) install from source for arm64 and find_package, 2) clone the repository and add matplot++ as a CMake subdirectory, or 3) use CMake FetchContent.

[yoonsik-jung-opt]

Thank you for your kindness answer! but unfortunately, I still not clear some points, then have a few questions.

I uninstalled the matplotplusplus via brew and changed my CMakeList.txt as using CMake subdirectory(I referenced https://alandefreitas.github.io/matplotplusplus/integration/cmake/embed-as-subdirectory/). It not only works for import the library, however, but also raises errors. (In CLion, it shows parameters of functions in matplot++, after successfully loaded matplot/matplot.h)

cmake_minimum_required(VERSION 3.21)
project(LADMH)
set(CMAKE_CXX_STANDARD 14)
add_subdirectory(matplotplusplus)

add_executable(LADMH main.cpp preprocessing.h pattern_generation.h utilities.h)
target_link_libraries(LADMH PUBLIC matplot)

====================[ Build | LADMH | Debug ]===================================
/Applications/CLion.app/Contents/bin/cmake/mac/bin/cmake --build /Users/yoonsikjung/Desktop/workspace/LADMH/cmake-build-debug --target LADMH
[2/3] Building CXX object CMakeFiles/LADMH.dir/main.cpp.o
FAILED: CMakeFiles/LADMH.dir/main.cpp.o 
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ -DMATPLOT_BUILD_HIGH_RESOLUTION_WORLD_MAP -DNOMINMAX -I/Users/yoonsikjung/Desktop/workspace/LADMH/matplotplusplus/source -g -arch arm64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.3.sdk -std=gnu++17 -MD -MT CMakeFiles/LADMH.dir/main.cpp.o -MF CMakeFiles/LADMH.dir/main.cpp.o.d -o CMakeFiles/LADMH.dir/main.cpp.o -c /Users/yoonsikjung/Desktop/workspace/LADMH/main.cpp
/Users/yoonsikjung/Desktop/workspace/LADMH/main.cpp:6:10: fatal error: 'CImg.h' file not found
#include "CImg.h"
         ^~~~~~~~
1 error generated.
ninja: build stopped: subcommand failed.

I tried to install cimg via brew, subdirectory, and source, but all tries are failed....How can I do for successfully load the CImg.h?

[alandefreitas]

Short answer: The problem here is you're attempting to include "CImg.h" in your program. But you didn't link the cimg library to your target. You might think linking to matplot would be enough, but cimg is a private dependency of matplot, which is not exposed to targets linking matplot. You should link the cimg target created by the matplot scripts or you could directly include the directory with cimg in your own target, depending on how you're using it.

The relevant script that creates the cimg target is here:

matplotplusplus/source/3rd_party/CMakeLists.txt

Line 54 in 8e1ca55

add_library(cimg INTERFACE)

Then it links that dependency with matplot as PRIVATE:

matplotplusplus/source/matplot/CMakeLists.txt

Line 104 in 8e1ca55

target_link_libraries_system(matplot

It sets the CIMG_INCLUDE_DIR variable and includes the target. As a starting point, you could output that and check if this matches the appropriate CImg directory. IF the cimg target is available, you can link that with your own target. At worst, you could use target_include_directories(LADMH PUBLIC ...) to include the CImg directory, wherever it is.