Phred33

[eledu]

Hi everyone!

I 've been searching for long time why subtract 33 in :

ord(<ASCII>)-33

but I cannot find the answer, somebody could please share a link, give some information where to find the answer or teach me why?

Many thanks in advance!!

[SNPsaurus]

If you want to represent the Phred score as an text character, then you need to use "letters". Look at the list of ASCII characters and what the first 32 represent https://theasciicode.com.ar/ascii-co...i-code-10.html

You don't want a quality score of 10 to be represented by a line feed, for example!