thing_sort.h

快速傅立叶变换程序代码,学信号的同学,可要注意了

typedef struct {
  int index ;
  int val ; 
} thing ; 
typedef struct {
  int index ;
  double val ; 
} dthing ; 
int cmp_thing ( const void * , const void * ) ; 
int cmp_dthing ( const void * , const void * ) ; 
/* the above for sorting;
  if want to sort doubles, code their vals up as ints first */