I have a set of experimental values. For instance, I have a value of 1120 pixels and I need to have some kind of factor z to multiply these 1120 pixels to get a value of approximately 1.15. Furthermore, I have 800 pixels and need to multiply this with the same factor z to get a value of approximately 1.2. Here are my experimental values:
1120 * z = approximately 1.15
800 * z = approx. 1.2
720 * z = approx. 1.25
640 * z = approx. 1.3
560 * z = approx. 1.4
480 * z = approx. 1.5
320 * z = approx. 2.0
I don't need values below 1.15 or above 2.0.
So my question is how I determine how big z is. This looks to me a little bit exponential, but I have no idea how to handle this in Objective-C. Any help would be very much appreciated.
It looked exponential to me as well. I figured this out using Grapher.
Since Grapher is bad at interpolating exponential functions, I plotted the points and modified an exponential equation till I got it pretty close. Then I entered the values I found as the starting point for the interpolation. The equation that you can use in your app is:
4.3069 * powf(M_E, -x/200.0f) + 1.1327f