In file included from test.c:33:
test_fdf.c: In function ‘test_fdf.constprop’:
test_fdf.c:311:25: warning: ‘/weighted’ directive writing 9 bytes into a region of size between 1 and 2048 [-Wformat-overflow=]
  311 |       sprintf(sname, "%s/weighted", buf);
      |                         ^~~~~~~~~
In file included from /usr/include/stdio.h:894,
                 from ../gsl/gsl_errno.h:23,
                 from ../gsl/gsl_vector_complex_long_double.h:25,
                 from ../gsl/gsl_vector.h:4,
                 from ../gsl/gsl_multilarge_nlinear.h:26,
                 from test.c:29:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:38:10: note: ‘__builtin___sprintf_chk’ output between 10 and 2057 bytes into a destination of size 2048
   38 |   return __builtin___sprintf_chk (__s, __USE_FORTIFY_LEVEL - 1,
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   39 |                                   __glibc_objsize (__s), __fmt,
      |                                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   40 |                                   __va_arg_pack ());
      |                                   ~~~~~~~~~~~~~~~~~
dwt.c: In function ‘main’:
dwt.c:26:7: warning: ignoring return value of ‘fscanf’ declared with attribute warn_unused_result’ [-Wunused-result]
   26 |       fscanf (f, "%lg", &orig_data[i]);
      |       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~