Probably a simple question, but my math is a bit rusty... I need a function which looks similar to logarithmic (fast rise at the beginning, then slows down). $f(0) = 0$, $f(b) = a$ ($a = 100$, $b = 2500$ but should be changeable, in between $500$-$5000$)
I don't need a horizontal asymptote because I'll cut off the values when $x$ reaches $b$.
Simply, I need it for my site for calculating a score as a percentage based on number of voters, which rises in a logarithmic fashion until $x$ reaches certain number ($500$-$5000$) and then it bumps the $100$ percent value. (thus giving new users instant gratification, and preventing score spamming for those with more votes).
I played with logarithmic functions but it's hard for me to get something which can be easily parametrized to easily change the parameter $b$ while keeping the flow.