CGAL file not found after installation - c++

I recently installed CGAL from their website. I used the native installer that is up to download on the website, and after selecting a directory, the installation completed. I am looking through the User Manual and trying to run some basic code, but I keep getting a compiler error. The code that I run is this (it is straight from the user manual):
// example: construct a quadratic program from data
// the QP below is the first quadratic program example in the user manual
#include <iostream>
#include <cassert>
#include <CGAL/basic.h>
#include <CGAL/QP_models.h>
#include <CGAL/QP_functions.h>
// choose exact integral type
#ifdef CGAL_USE_GMP
#include <CGAL/Gmpz.h>
typedef CGAL::Gmpz ET;
#else
#include <CGAL/MP_Float.h>
typedef CGAL::MP_Float ET;
#endif
int main()
{
}
It is just a simple QP problem, using the syntax straight from the website. However, when I try to run it, I receive this compiler error:
C:\...\include\CGAL\config.h|161|fatal error: CGAL/compiler_config.h: No such file or directory|
I used the installer straight from the website, but CGAL is still giving me these issues. Does anyone know how to solve it? Thank you.

According to the documentation (https://doc.cgal.org/latest/Manual/installation.html#title5), after installing CGAL on Windows, you still need to build the library itself.
This process will (I suspect) create the missing configuration files according to the compiler you have (gcc 7.3).

Related

Error while compiling eigen program: error: 'seq' is not a member of 'Eigen'

I am trying to index a matrix in indexes which follow an arithmetic sequence. According to the Eigen tutorial on the official website, I should use Eigen::seq(firstVal, lastVal, step) to generate this sequence. After calling this the error, as pasted in the title of this thread pops up.
I checked all the files of my local eigen folder, for the 'seq' method, but no luck. It wasn't anywhere. I guess this means that some file is missing, right?
Code goes smth like this.
Headers at the top
#include <iostream>
#include <string>
#include <chrono>
#include "Eigen/Dense"
#include "Eigen/Core"
#include <cmath>
#include <random>
m1(row, Eigen::seq(some_index*m1.cols(), some_index*m1.cols() + m1.cols()-1, step))= m2.block(row, 0, 1, m2.cols());
where of course, m1.cols() >> m2.cols()
Error output:
error: 'seq' is not a member of 'Eigen'
The expected result would be to get the row from matrix m2 (where m2.cols() < m1.cols()) and assign the row's values to certain indexes in the same row number of m1.
After inspecting the official repo
https://bitbucket.org/eigen/eigen/src/default/
The required function is in the file Eigen/src/core/ArithmeticSequence.h which is included in the general header Eigen/Core already used in the snippet.
The issue seems to be that OP downloaded Eigen from a third-party repo not in sync with the main repo and the aforementioned file was missing.
I add this note for posterity: The latest stable release at the moment of writing is 3.3.7, released in 2018, (see http://eigen.tuxfamily.org/index.php?title=Main_Page), and does not include the file. So, if anybody else finds the same issue, please try to clone the official repo.
The required function is in the file Eigen/src/core/ArithmeticSequence.h which is included in the general header Eigen/Core. So #include "Eigen/Core will suffice. (As #CuriouslyRecurringThoughts pointed out).
However, to address the confusion in his answer: ArithmeticSequences such as Seq are planned for Eigen version 3.4.0 So they are not present in versions prior to this. When I write this, the latest official release is 3.3.9 which thus doesn't support ArithmeticSequences.
If you look in the official repo, you will find that the file is also not present for release 3.3.9 and earlier. Right now, it is only included in the 3.4.0-rc1 and master branch.
So to answer your question: You are most likely using an older version of Eigen and you will need to use Eigen 3.4.0-rc1 or later.

Struggling with dlib, linker errors and save_jpeg in XCode

First, I am new to C++ and dlib but I have successfully built the examples and started working on my own project. Things have been progressing smoothly until I try to save a jpeg. Attempting to compile code using dlib::save_jpeg throws a linker error and I cannot track down the solution. I have attempted to add #define DLIB_JPEG_SUPPORT above and below my #includes but no luck. I am using XCode and used cmake -G "Xcode" .. when I compiled the examples. Relevant code below. Since I am on a Mac, I have added header and library search paths for X11 (for dlib gui), OpenCV, and DLIB. I have libjpeg.dylib and linked that to my project with and without #define DLIB_JPEG_SUPPORT in main.cpp. Is there some other build setting I need to specify? Thank you in advance for your help.
Finally, I have seen other questions and pages about dlib and libjpeg issues but no luck yet. And yes I have source.cpp included in the project.
// the standard stuff
#include <string>
#include <iostream>
#include <unistd.h>
// opencv mat object
#include <opencv2/opencv.hpp>
// dlib>
#include <dlib/opencv.h>
#include <dlib/image_io.h>
#include <dlib/gui_widgets.h>
#include <dlib/image_transforms.h>
int main(int argc, const char * argv[]) {
// retrieving images from a TCP connection
// decode data stream
img = cv::imdecode(rawImage, CV_LOAD_IMAGE_COLOR);
// perform image processing
dlib::cv_image<dlib::bgr_pixel> d_image(img);
// finally save the result to jpg
std::string fname = argv[1] + std::to_string(image_id) + ".jpg";
dlib::save_jpeg(d_image, fname); // <- line that won't compile
return 0;
}
After quit a bit of struggling and side-by-side comparisons I finally found the issue. In XCode go to to Build Settings and modify Other Linker Flags, Run Search Paths, and Other C++ Flags to match the compiled and working face_ex example. I wholesale copied all of those flags and included a missing libjpeg.dylib and was able to get things running. It should look something like this for the C++ flags . Hope this helps the next person.

Including <string> in c++ using Netbeans

Netbeans fails compilation on:
#include <string>
Output says:
main.c:10:18: fatal error: string: No such file or directory
#include <string>
The previous two declarations are included fine:
#include <stdio.h>
#include <stdlib.h>
I have removed all the code afterwards to make sure.
I am using cygwin_64 and it installed as per Netbeans c++ installation manual and shows versions in CLI
I am new to C++ and I know there have been similar questions, but the answers didn't help me.
Just try to create new project and follow these steps:
Click File->Create project.
Choose C/C++, then C/C++ application, click Next.
Enter project name and in the right choose C++ in combobox. Or C++11.

C++ project build, but IDE shows error

Error: cannot open source file "GL/glew.h"
I have the following code :
//Include GLEW
#include <GL/glew.h>
//Include GLFW
#include <GLFW/glfw3.h>
//Include the standard C++ headers
#include <stdio.h>
#include <stdlib.h>
//Define an error callback
static void error_callback(int error, const char* description)
{
...
I took from there: http://www.41post.com/5178/programming/opengl-configuring-glfw-and-glew-in-visual-cplusplus-express#part4
In order to have a somewhat portable solution, before I even started Visual Studio 2013 I created two System Environment Variable in windows.
GLEW=C:\Install\Development\C++\Framework\glew-1.10.0-win32\glew-1.10.0
GLFW=C:\Install\Development\C++\Framework\glfw-3.0.4.bin.WIN32\glfw-3.0.4.bin.WIN32
So in my project I could for instance write a additional include folder as: %GLEW%\include
As I said, it builds fine and runs fine as well.
Yet, not having intellisense behave properly is really annoying.
How to fix it?
My syntax was actually wrong, you cant use global environment variable in VS using %<name>% but you have to use $(%<name>).
Wherever I wrote %GLEW%\include I should have $(GLEW)\include.
It's working fine now.
Though I'm completely clueless why it built.
This post: https://stackoverflow.com/a/11543754/910813 got me to remind that.

Boost build error with websocketpp and MySQL on Windows

I am trying to build a C++ app that uses both websocketpp and MySQL. I have encountered 2 build problems using VS 2010 C++ Express.
1) A problem with the boost libraries. It produces many errors like this:
1>c:\program files (x86)\boost\boost_1_50\boost\thread\win32\thread_data.hpp(210): error C2146: syntax error : missing ')' before identifier 'rel_time'
Here's the relevant snippet from thread_data.hpp starting with line 210:
inline BOOST_SYMBOL_VISIBLE void sleep(TimeDuration const& rel_time)
{
interruptible_wait(detail::pin_to_zero(rel_time.total_milliseconds()));
}
2) A conflict with the word VERSION which is documented here and I believe is independent.
To make a clear and simple example of the boost build problems, I'm using the websocketpp example: echo_server.cpp to which I added these includes:
#include "stdafx.h"
Boost lib includes recommended by "Building a program with websocketpp" on the websocketpp site.
#include <boost/regex.hpp>
#include <boost/random.hpp>
#include <boost/system/api_config.hpp>
#include <boost/system/config.hpp>
#include <boost/system/error_code.hpp>
#include <boost/system/system_error.hpp>
#include <boost/system/windows_error.hpp>
and the MySQL header includes. Adding these 2 boostincludes triggers the build errors. If I comment out these 2 includes, it builds without errors:
#include <my_global.h>
#include <mysql.h>
Any suggestions on how to deal with the boost problems?
I don't think this is the same build problem as this one, "Trying to build websocket++ with MinGW: last few linker errors — what could it be?"
Concerning the first error, check if there are any macros interfering with the code. Right-click and go to definition or #define the macro yourself at the beginning of the file and see where it gets redefined. In really hard cases, look at the preprocessor output via a compiler flag.
Concerning the rest, you don't provide any versions for Boost and MySQL. Then, there is my_global.h (or is that part of MySQL?) and stdafx.h, which are both under your control but you don't show them here. Also, try to reduce the issue to the smallest possible piece of code. In short, provide a reproducible example.