Thankyou once again m1xram for your detailed & insightful ideas.

Your code does a great job and actually outputs much more information that I had expected - but thats because of my superficial problem description. Nonetheless, it will be a valuable resource for me.

In the interim I did some tinkering with my crude code, and it seems to work too - though outputting much less. What I ultimately was trying to achieve was to insert a new field that calculates the frequency of "," or "." in my string relative to "[a-zA-Z]" - BUT once all those same characters with either $ or ~^ next to them had been removed (those extra characters act as indicators/modifiers of their adjacent character).

Despite what I'd thought, split does seem to search for groups of characters if you enclose them in parentheses.

This is my input data:

Code:

153-0	29	A	M	85	85	60	6	CC..,.	gggggg 0.667 
153-0	37	A	W	83	83	60	6	TT..,.	geggdg 0.667 
153-0	85	G	R	80	80	60	6	AA..,.	aggggg 0.667 
153-0	98	G	R	129	129	60	6	A$A$A.,.	`geggg 0.500 
176-0	48	A	W	82	82	60	7	.$TT,..,	ggggegg 0.714

$8 is the stringof interest. $7 is the number of "characters" in $8, where a character with a modifier like A$ is treated as one single character. $9 is the frequency of . or , in the $8 string.

The code I used was:

Code:

{consends = split($8, a, "((\\.\\$)|(\\,\\$)|(\\^~\\.)|(\\^~,))");
allends = split($8, a, "[\\$]|[\\^~]");
consall = split($8, a, "[\\.,]");
readnotend = $7-(allends-1);
if (readnotend == 0.000) {printf ("%s %s %s\n", $0, "1.000", readnotend)} else {printf ("%s %3.3f %s\n", $0, ((consall-1)-(consends-1))/($7-(allends-1)), readnotend);
}
}

Which gave me an outputs of:

Code:

153-0	29	A	M	85	85	60	6	CC..,.	gggggg 0.667 0.667 6
153-0	37	A	W	83	83	60	6	TT..,.	geggdg 0.667 0.667 6
153-0	85	G	R	80	80	60	6	AA..,.	aggggg 0.667 0.667 6
153-0	98	G	R	129	129	60	6	A$A$A.,.	`geggg 0.500 0.750 4
176-0	48	A	W	82	82	60	7	.$TT,..,	ggggegg 0.714 0.667 6

This adds the new frequencies, and the number of "non-modified" characters in the $8 string. You can see that where there are $ in the string the new & old frequencies differ as does the number of "characters" in the string, but otherwise they remain unchanged.

Cheers,

Olly