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Function: index_cmp()

0 int index_cmp(const void *f1, const void *f2)
This is a function which may be used to compare the indexes of two different objects of type struct removed_lines. It is used for example as an argument to the standard-C library routine qsort for sorting lists of removed lines into increasing order in frequency.

This function is supplied with pointers to two stuctures. It returns -1 if the first structure has the smaller index, +1 if the first structure has the larger index, and 0 if the indexes are equal.

The arguments are:

f1: Input. Pointer to the first structure of type struct removed_lines (cast to void * so that your compiler does not complain).
f2: Input. Pointer to the second structure of type struct removed_lines (cast to void * so that your compiler does not complain).

As an example, if line_list[0..n-1] is an array of struct removed_lines, then the function call:
qsort(line_list,n,sizeof(struct significant_values),index_cmp)
will sort that array into increasing index (frequency!) order. (Note: you may have to cast the arguments to prevent your compiler from complaining.)

Author: Bruce Allen (ballen@dirac.phys.uwm.edu) and Adrian Ottewill (ottewill@relativity.ucd.ie).
Comments: None.


next up previous contents
Next: Function: remove_spectral_lines() Up: GRASP Routines: General purpose Previous: Function: fvalue_cmp()   Contents
Bruce Allen 2000-11-19