How to create a mathematical function from data plots : <p>I am by no means a math person, but I am really trying to figure out how create a graphable function from some data plots I measure from a chemical titration. I have been trying to learn R and I would like to know if anyone can explain to me or point me to a guide to create a mathmatic function of the titration graph below. 
Thanks in advance.
<a href="https://i.stack.imgur.com/EbOsp.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EbOsp.png" alt="mL Base V Acid Solution"></a></p>
