How to compile code?

Get the following error:

`$ clang++ -v -g /home/user/Eigetron/eigetron.cpp -o /home/user/Eigetron/eigetron $(pkg-config --cflags --libs opencv4) -I /usr/local/include/opencv4/ -lncurses -I /usr/local/include/ -L /usr/local/lib/`

```
/home/user/Eigetron/eigetron.cpp:156:38: error: reference to non-static member function must be called; did you mean to call it with no arguments?
normalized_m[i] = new double[ mean.width * mean.height ];
~~~~~^~~~~
()
/home/user/Eigetron/eigetron.cpp:156:51: error: reference to non-static member function must be called; did you mean to call it with no arguments?
normalized_m[i] = new double[ mean.width * mean.height ];
~~~~~^~~~~~
()
/home/user/Eigetron/eigetron.cpp:167:53: error: reference to non-static member function must be called; did you mean to call it with no arguments?
eigen_covariance( normalized_m, covariance_m, mean.width * mean.height, trainingset.size() );
~~~~~^~~~~
()
/home/user/Eigetron/eigetron.cpp:167:66: error: reference to non-static member function must be called; did you mean to call it with no arguments?
eigen_covariance( normalized_m, covariance_m, mean.width * mean.height, trainingset.size() );
~~~~~^~~~~~
()
/home/user/Eigetron/eigetron.cpp:180:82: error: reference to non-static member function must be called; did you mean to call it with no arguments?
eigenprojections = eigen_project( normalized_m, eigenvectors, eigenvalues, mean.width * mean.height, trainingset.size() );
~~~~~^~~~~
()
/home/user/Eigetron/eigetron.cpp:180:95: error: reference to non-static member function must be called; did you mean to call it with no arguments?
eigenprojections = eigen_project( normalized_m, eigenvectors, eigenvalues, mean.width * mean.height, trainingset.size() );
~~~~~^~~~~~
()
/home/user/Eigetron/eigetron.cpp:204:19: error: reference to non-static member function must be called; did you mean to call it with no arguments?
db.width = mean.width;
~~~~~^~~~~
()
/home/user/Eigetron/eigetron.cpp:205:19: error: reference to non-static member function must be called; did you mean to call it with no arguments?
db.height = mean.height;
~~~~~^~~~~~
()
/home/user/Eigetron/eigetron.cpp:214:24: error: reference to non-static member function must be called; did you mean to call it with no arguments?
for( i = 0; i < image.width; i++ ){
~~~~~~^~~~~
()
/home/user/Eigetron/eigetron.cpp:215:25: error: reference to non-static member function must be called; did you mean to call it with no arguments?
for( j = 0; j < image.height; j++ ){
~~~~~~^~~~~~
()
/home/user/Eigetron/eigetron.cpp:216:12: error: no member named 'ptr' in 'cimg_library::CImg'
*mean.ptr( i, j ) += *image.ptr( i, j ) / (trainingset_size - 1);
~~~~ ^
/home/user/Eigetron/eigetron.cpp:216:34: error: no member named 'ptr' in 'cimg_library::CImg'
*mean.ptr( i, j ) += *image.ptr( i, j ) / (trainingset_size - 1);
~~~~~ ^
/home/user/Eigetron/eigetron.cpp:224:31: error: reference to non-static member function must be called; did you mean to call it with no arguments?
for( i = 0, k = 0; i < image.width; i++ ){
~~~~~~^~~~~
()
/home/user/Eigetron/eigetron.cpp:225:25: error: reference to non-static member function must be called; did you mean to call it with no arguments?
for( j = 0; j < image.height; j++, k++ ){
~~~~~~^~~~~~
()
/home/user/Eigetron/eigetron.cpp:226:36: error: no member named 'ptr' in 'cimg_library::CImg'
normalized_m[index][k] = *image.ptr( i, j ) - *mean.ptr( i, j );
~~~~~ ^
/home/user/Eigetron/eigetron.cpp:226:56: error: no member named 'ptr' in 'cimg_library::CImg'
normalized_m[index][k] = *image.ptr( i, j ) - *mean.ptr( i, j );
~~~~ ^
/home/user/Eigetron/eigetron.cpp:468:37: error: reference to non-static member function must be called; did you mean to call it with no arguments?
for( m = 0, i = 0; m < normalized.width; m++ ){
~~~~~~~~~~~^~~~~
()
/home/user/Eigetron/eigetron.cpp:469:31: error: reference to non-static member function must be called; did you mean to call it with no arguments?
for( n = 0; n < normalized.height; n++, i++ ){
~~~~~~~~~~~^~~~~~
()
/home/user/Eigetron/eigetron.cpp:470:46: error: no member named 'ptr' in 'cimg_library::CImg'
w += projections[index][i] * *normalized.ptr(m,n);
~~~~~~~~~~ ^
19 errors generated.
```

Thanks.