Subject: Knowing the geometry changes of a string, how to calculate new tension?

You have a violin string at a known initial frequency, tension and 
mass/length, ie. knowing everything. You retune another string on teh 
same bridge, and thus changing the geometry of this string as well 
(it becomes a bit shorter). If you know the new geometry of the 
possition of the string(by use of laser), and everything else except 
the tension and frequency in the string is known, how is the relation 
between the geometry (length, mass per length, etc) of the string 
compared to the tension in the string, and how can this be calculated?

Greetings Kirsten

Re: Knowing the geometry changes of a string, how to calculate new tension?