Program received signal SIGSEGV, Segmentation fault.
0x00000000004095e1 in col (col_num=24, this=0x8000000000000000)
    at /usr/include/armadillo_bits/Mat_meat.hpp:2588
2588	  arma_debug_check( col_num >= n_cols, "Mat::col(): index out of bounds");
(gdb) backtrace
#0  0x00000000004095e1 in col (col_num=24, this=0x8000000000000000)
    at /usr/include/armadillo_bits/Mat_meat.hpp:2588
#1  MyFunction::Evaluate (this=0x8000000000000000, coordinates=..., i=24)
    at find_equ.cpp:40
#2  0x000000000040d56a in mlpack::optimization::SGD<MyFunction>::Optimize (
    this=0x7fffffffe2b0, iterate=...)
    at /usr/local/include/mlpack/core/optimizers/sgd/sgd_impl.hpp:100
#3  0x8000000000c53134 in ?? ()
#4  0x8000000000000000 in ?? ()
#5  0xbf1e1ddf0f6194c4 in ?? ()
#6  0x800213416a6aaedb in ?? ()
#7  0x8002317e77445ca2 in ?? ()
#8  0x8000000000000000 in ?? ()
#9  0x3eff75104d551d69 in ?? ()
#10 0x0000000000002710 in ?? ()
#11 0x3e112e0be826d695 in ?? ()
#12 0x00007fff00000000 in ?? ()
#13 0x00007ffff7ffe1c8 in _r_debug ()
#14 0x0000003a00000003 in ?? ()
#15 0x00000000000000ae in ?? ()
#16 0x000000000062b460 in ?? ()
#17 0x00000000f63d4e2e in ?? ()
#18 0x0000000000000000 in ?? ()