// wc_complement() - create W/C string to seq.
string	wc_complement( string seq, string rlib, string rlt )
//    (note the rlib is unused: just there for backwards compatibility)
{
	string	acbase, base, wcbase, wcseq;
	int	i, len;

	if( rlt == "dna" )
		acbase = "t";
	else if( rlt == "rna" )
		acbase = "u";
	else{
		fprintf( stderr,
		"wc_complement: rlt (%s) is not dna/rna, has no W/C complement\n",
			rlt );
		exit( 1 );
	}
	
	len = length( seq );
	wcseq = NULL;
	for( i = 1; i <= len; i = i + 1 ){
		base = substr( seq, i, 1 );
		if( base == "a" || base == "A" )
			wcbase = acbase;
		else if( base == "c" || base == "C" )
			wcbase = "g";
		else if( base == "g" || base == "G" )
			wcbase = "c";
		else if( base == "t" || base == "T" )
			wcbase = "a";
		else if( base == "u" || base == "U" )
			wcbase = "a";
		else{
			fprintf( stderr, "wc_complement: unknown base %s\n",
				base );
			exit( 1 );
		}
		wcseq = wcseq + wcbase;
	}
	return( wcseq );
};