not able to compile the provided examples

[rajkamal-007]

Hi,
I've followed the installation guide and I was trying to run the xor_sample.cpp example on ubuntu 16.04 LTS. the error messages are as follows:
xor_sample.cpp: In function ‘int print_callback(FANN::neural_net&, FANN::training_data&, unsigned int, unsigned int, float, unsigned int, void*)’:
xor_sample.cpp:42:64: warning: unused parameter ‘train’ [-Wunused-parameter]
42 | int print_callback(FANN::neural_net &net, FANN::training_data &train,
| ~~~~~~~~~~~~~~~~~~~~~^~~~~
xor_sample.cpp:43:18: warning: unused parameter ‘max_epochs’ [-Wunused-parameter]
43 | unsigned int max_epochs, unsigned int epochs_between_reports,
| ~~~~~~~~~~~~~^~~~~~~~~~
xor_sample.cpp:43:43: warning: unused parameter ‘epochs_between_reports’ [-Wunused-parameter]
43 | unsigned int max_epochs, unsigned int epochs_between_reports,
| ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
xor_sample.cpp:44:11: warning: unused parameter ‘desired_error’ [-Wunused-parameter]
44 | float desired_error, unsigned int epochs, void user_data)
| ~~~~~~^~~~~~~~~~~~~
xor_sample.cpp:44:53: warning: unused parameter ‘user_data’ [-Wunused-parameter]
44 | float desired_error, unsigned int epochs, void user_data)
| ~~~~~~^~~~~~~~~
xor_sample.cpp: In function ‘int main(int, char)’:
xor_sample.cpp:138:14: warning: unused parameter ‘argc’ [-Wunused-parameter]
138 | int main(int argc, char **argv)
| ~~~~^~~~
xor_sample.cpp:138:27: warning: unused parameter ‘argv’ [-Wunused-parameter]
138 | int main(int argc, char argv)
| ~~~~~~~^~~~
/tmp/ccIST7S8.o: In function FANN::training_data::destroy_train()': xor_sample.cpp:(.text._ZN4FANN13training_data13destroy_trainEv[_ZN4FANN13training_data13destroy_trainEv]+0x23): undefined reference to fann_destroy_train'
/tmp/ccIST7S8.o: In function FANN::training_data::read_train_from_file(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)': xor_sample.cpp:(.text._ZN4FANN13training_data20read_train_from_fileERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE[_ZN4FANN13training_data20read_train_from_fileERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE]+0x2c): undefined reference to fann_read_train_from_file'
/tmp/ccIST7S8.o: In function FANN::training_data::save_train_to_fixed(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, unsigned int)': xor_sample.cpp:(.text._ZN4FANN13training_data19save_train_to_fixedERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEj[_ZN4FANN13training_data19save_train_to_fixedERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEj]+0x46): undefined reference to fann_save_train_to_fixed'
/tmp/ccIST7S8.o: In function FANN::training_data::length_train_data()': xor_sample.cpp:(.text._ZN4FANN13training_data17length_train_dataEv[_ZN4FANN13training_data17length_train_dataEv]+0x2a): undefined reference to fann_length_train_data'
/tmp/ccIST7S8.o: In function FANN::neural_net::destroy()': xor_sample.cpp:(.text._ZN4FANN10neural_net7destroyEv[_ZN4FANN10neural_net7destroyEv]+0x23): undefined reference to fann_get_user_data'
xor_sample.cpp:(.text._ZN4FANN10neural_net7destroyEv[_ZN4FANN10neural_net7destroyEv]+0x4e): undefined reference to fann_destroy' /tmp/ccIST7S8.o: In function FANN::neural_net::create_standard_array(unsigned int, unsigned int const)':
xor_sample.cpp:(.text._ZN4FANN10neural_net21create_standard_arrayEjPKj[_ZN4FANN10neural_net21create_standard_arrayEjPKj]+0x2c): undefined reference to fann_create_standard_array' /tmp/ccIST7S8.o: In function FANN::neural_net::run(float)':
xor_sample.cpp:(.text._ZN4FANN10neural_net3runEPf[_ZN4FANN10neural_net3runEPf]+0x35): undefined reference to fann_run' /tmp/ccIST7S8.o: In function FANN::neural_net::init_weights(FANN::training_data const&)':
xor_sample.cpp:(.text._ZN4FANN10neural_net12init_weightsERKNS_13training_dataE[_ZN4FANN10neural_net12init_weightsERKNS_13training_dataE]+0x3d): undefined reference to fann_init_weights' /tmp/ccIST7S8.o: In function FANN::neural_net::save(std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&)':
xor_sample.cpp:(.text._ZN4FANN10neural_net4saveERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE[_ZN4FANN10neural_net4saveERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE]+0x40): undefined reference to fann_save' /tmp/ccIST7S8.o: In function FANN::neural_net::save_to_fixed(std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&)':
xor_sample.cpp:(.text._ZN4FANN10neural_net13save_to_fixedERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE[_ZN4FANN10neural_net13save_to_fixedERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE]+0x40): undefined reference to fann_save_to_fixed' /tmp/ccIST7S8.o: In function FANN::neural_net::train_on_data(FANN::training_data const&, unsigned int, unsigned int, float)':
xor_sample.cpp:(.text._ZN4FANN10neural_net13train_on_dataERKNS_13training_dataEjjf[_ZN4FANN10neural_net13train_on_dataERKNS_13training_dataEjjf]+0x52): undefined reference to fann_train_on_data' /tmp/ccIST7S8.o: In function FANN::neural_net::get_MSE()':
xor_sample.cpp:(.text._ZN4FANN10neural_net7get_MSEEv[_ZN4FANN10neural_net7get_MSEEv]+0x2c): undefined reference to fann_get_MSE' /tmp/ccIST7S8.o: In function FANN::neural_net::set_callback(int ()(FANN::neural_net&, FANN::training_data&, unsigned int, unsigned int, float, unsigned int, void), void*)':
xor_sample.cpp:(.text.ZN4FANN10neural_net12set_callbackEPFiRS0_RNS_13training_dataEjjfjPvES4[ZN4FANN10neural_net12set_callbackEPFiRS0_RNS_13training_dataEjjfjPvES4]+0x2f): undefined reference to fann_get_user_data' xor_sample.cpp:(.text._ZN4FANN10neural_net12set_callbackEPFiRS0_RNS_13training_dataEjjfjPvES4_[_ZN4FANN10neural_net12set_callbackEPFiRS0_RNS_13training_dataEjjfjPvES4_]+0xa9): undefined reference to fann_set_user_data'
xor_sample.cpp:(.text.ZN4FANN10neural_net12set_callbackEPFiRS0_RNS_13training_dataEjjfjPvES4[ZN4FANN10neural_net12set_callbackEPFiRS0_RNS_13training_dataEjjfjPvES4]+0xc4): undefined reference to fann_set_callback' xor_sample.cpp:(.text._ZN4FANN10neural_net12set_callbackEPFiRS0_RNS_13training_dataEjjfjPvES4_[_ZN4FANN10neural_net12set_callbackEPFiRS0_RNS_13training_dataEjjfjPvES4_]+0xda): undefined reference to fann_set_callback'
/tmp/ccIST7S8.o: In function FANN::neural_net::print_parameters()': xor_sample.cpp:(.text._ZN4FANN10neural_net16print_parametersEv[_ZN4FANN10neural_net16print_parametersEv]+0x23): undefined reference to fann_print_parameters'
/tmp/ccIST7S8.o: In function FANN::neural_net::set_learning_rate(float)': xor_sample.cpp:(.text._ZN4FANN10neural_net17set_learning_rateEf[_ZN4FANN10neural_net17set_learning_rateEf]+0x2f): undefined reference to fann_set_learning_rate'
/tmp/ccIST7S8.o: In function FANN::neural_net::set_activation_function_hidden(FANN::activation_function_enum)': xor_sample.cpp:(.text._ZN4FANN10neural_net30set_activation_function_hiddenENS_24activation_function_enumE[_ZN4FANN10neural_net30set_activation_function_hiddenENS_24activation_function_enumE]+0x2b): undefined reference to fann_set_activation_function_hidden'
/tmp/ccIST7S8.o: In function FANN::neural_net::set_activation_function_output(FANN::activation_function_enum)': xor_sample.cpp:(.text._ZN4FANN10neural_net30set_activation_function_outputENS_24activation_function_enumE[_ZN4FANN10neural_net30set_activation_function_outputENS_24activation_function_enumE]+0x2b): undefined reference to fann_set_activation_function_output'
/tmp/ccIST7S8.o: In function FANN::neural_net::set_activation_steepness_hidden(float)': xor_sample.cpp:(.text._ZN4FANN10neural_net31set_activation_steepness_hiddenEf[_ZN4FANN10neural_net31set_activation_steepness_hiddenEf]+0x2f): undefined reference to fann_set_activation_steepness_hidden'
/tmp/ccIST7S8.o: In function FANN::neural_net::set_activation_steepness_output(float)': xor_sample.cpp:(.text._ZN4FANN10neural_net31set_activation_steepness_outputEf[_ZN4FANN10neural_net31set_activation_steepness_outputEf]+0x2f): undefined reference to fann_set_activation_steepness_output'
/tmp/ccIST7S8.o: In function FANN::neural_net::get_network_type()': xor_sample.cpp:(.text._ZN4FANN10neural_net16get_network_typeEv[_ZN4FANN10neural_net16get_network_typeEv]+0x2a): undefined reference to fann_get_network_type'
/tmp/ccIST7S8.o: In function FANN::neural_net::internal_callback(fann*, fann_train_data*, unsigned int, unsigned int, float, unsigned int)': xor_sample.cpp:(.text._ZN4FANN10neural_net17internal_callbackEP4fannP15fann_train_datajjfj[_ZN4FANN10neural_net17internal_callbackEP4fannP15fann_train_datajjfj]+0x37): undefined reference to fann_get_user_data'
collect2: error: ld returned 1 exit status

Thank you,
Raj Kamal