我正在尝试使用遗传算法编写程序，这是一种特定类型的优化算法。我为此任务找到了一个名为“进化对象”的免费库，并实现了一个非常简单的遗传算法实例。程序代码、netbeans 实现的构建命令，以及最后我收到的错误消息都发布在下面的单独块中。如果您允许我帮忙，您会发现 cout 函数出了点问题。当我在互联网上搜索类似的困难时，我发现人们一直在通过简单地使用 g++ 而不是 gcc 来解决问题，但我已经在使用 g++，如您所见。任何帮助，将不胜感激....
程序代码如下：
#include <stdexcept>
#include <iostream>
#include <eo>
#include <ga.h>
typedef eoBit<double> Indi;
double binary_value(const Indi & _indi)
{
double sum = 0;
for (unsigned i = 0; i < _indi.size(); i++)
sum += _indi[i];
return sum;
}
void main_function(int argc, char **argv)
{
const unsigned int SEED = 42; // seed for random number generator
const unsigned int T_SIZE = 3; // size for tournament selection
const unsigned int VEC_SIZE = 16; // Number of bits in genotypes
const unsigned int POP_SIZE = 100; // Size of population
const unsigned int MAX_GEN = 400; // Maximum number of generation before STOP
const float CROSS_RATE = 0.8; // Crossover rate
const double P_MUT_PER_BIT = 0.01; // probability of bit-flip mutation
const float MUT_RATE = 1.0; // mutation rate
rng.reseed(SEED);
eoEvalFuncPtr<Indi> eval( binary_value );
eoPop<Indi> pop;
for (unsigned int igeno=0; igeno<POP_SIZE; igeno++)
{
Indi v; // void individual, to be filled
for (unsigned ivar=0; ivar<VEC_SIZE; ivar++)
{
bool r = rng.flip(); // new value, random in {0,1}
v.push_back(r); // append that random value to v
}
eval(v); // evaluate it
pop.push_back(v); // and put it in the population
}
pop.sort();
cout << "Initial Population" << endl;
cout << pop;
eoDetTournamentSelect<Indi> select(T_SIZE); // T_SIZE in [2,POP_SIZE]
eo1PtBitXover<Indi> xover;
eoBitMutation<Indi> mutation(P_MUT_PER_BIT);
eoGenContinue<Indi> continuator(MAX_GEN);
eoSGA<Indi> gga(select, xover, CROSS_RATE, mutation, MUT_RATE, eval, continuator);
gga(pop);
pop.sort();
cout << "FINAL Population\n" << pop << endl;
}
int main(int argc, char **argv)
{
main_function(argc, argv);
return 1;
}
}
Netbeans 向我展示了它在尝试构建时正在这样做：
make[1]: Entering directory `/home/gregemerson/EO_GA/EO_GA'
rm -f -r build/Debug
rm -f dist/Debug/GNU-Linux-x86/eo_ga
make[1]: Leaving directory `/home/gregemerson/EO_GA/EO_GA'
CLEAN SUCCESSFUL (total time: 94ms)
"/usr/bin/make" -f nbproject/Makefile-Debug.mk QMAKE= SUBPROJECTS= .build-conf
make[1]: Entering directory `/home/gregemerson/EO_GA/EO_GA'
"/usr/bin/make" -f nbproject/Makefile-Debug.mk dist/Debug/GNU-Linux-x86/eo_ga
make[2]: Entering directory `/home/gregemerson/EO_GA/EO_GA'
mkdir -p build/Debug/GNU-Linux-x86
rm -f build/Debug/GNU-Linux-x86/main.o.d
g++ -c -g -I../../EO/EO/eo/src -MMD -MP -MF build/Debug/GNU-Linux-x86/main.o.d -o build/Debug/GNU-Linux-x86/main.o main.cpp
mkdir -p dist/Debug/GNU-Linux-x86
g++ -o dist/Debug/GNU-Linux-x86/eo_ga build/Debug/GNU-Linux-x86/main.o -L../../EO/EO/eo/build/lib /home/gregemerson/EO/EO/eo/build/lib/libcma.a /home/gregemerson/EO/EO/eo/build/lib/libeoutils.a /home/gregemerson/EO/EO/eo/build/lib/libes.a /home/gregemerson/EO/EO/eo/build/lib/libga.a
错误消息如下：
/home/gregemerson/EO_GA/EO_GA/main.cpp:94: undefined reference to `operator<<(std::basic_ostream<char, std::char_traits<char> >&, eoPrintable const&)'
/home/gregemerson/EO_GA/EO_GA/main.cpp:99: undefined reference to `operator<<(std::basic_ostream<char, std::char_traits<char> >&, eoPrintable const&)'
/home/gregemerson/EO_GA/EO_GA/main.cpp:149: undefined reference to `operator<<(std::basic_ostream<char, std::char_traits<char> >&, eoPrintable const&)'
build/Debug/GNU-Linux-x86/main.o: In function `eoPop<eoBit<double> >::sortedPrintOn(std::basic_ostream<char, std::char_traits<char> >&) const':
/home/gregemerson/EO_GA/EO_GA/../../EO/EO/eo/src/eoPop.h:294: undefined reference to `operator<<(std::basic_ostream<char, std::char_traits<char> >&, eoPrintable const&)'
build/Debug/GNU-Linux-x86/main.o: In function `std::ostream_iterator<eoBit<double>, char, std::char_traits<char> >::operator=(eoBit<double> const&)':
/usr/include/c++/4.6/bits/stream_iterator.h:198: undefined reference to `operator<<(std::basic_ostream<char, std::char_traits<char> >&, eoPrintable const&)'
collect2: ld returned 1 exit status
make[2]: *** [dist/Debug/GNU-Linux-x86/eo_ga] Error 1
make[2]: Leaving directory `/home/gregemerson/EO_GA/EO_GA'
make[1]: *** [.build-conf] Error 2
make[1]: Leaving directory `/home/gregemerson/EO_GA/EO_GA'
make: *** [.build-impl] Error 2
您的回答确实解决了我的 cout(pop) 问题。但是，我现在在我正在使用的一个静态库的标头中看到类似的错误，以及看起来与基本 c++ 库之一相关的内容。我得到以下。你能理解这个吗？
build/Debug/GNU-Linux-x86/main.o: In function `std::ostream_iterator<eoBit<double>, char, std::char_traits<char> >::operator=(eoBit<double> const&)':
/usr/include/c++/4.6/bits/stream_iterator.h:198: undefined reference to `operator<<(std::basic_ostream<char, std::char_traits<char> >&, eoPrintable const&)'
build/Debug/GNU-Linux-x86/main.o: In function `eoPop<eoBit<double> >::sortedPrintOn(std::basic_ostream<char, std::char_traits<char> >&) const':
/home/gregemerson/EO_GA/EO_GA/../../EO/EO/eo/src/eoPop.h:294: undefined reference to `operator<<(std::basic_ostream<char, std::char_traits<char> >&, eoPrintable const&)'