# Generating the best-fit formula for given data

I have three independent variables and one dependent variable, I want to generate a new formula for calculating the dependent one using the three independent ones, I have the data series like below:

x(1), x(11), x(111), y(1)
x(2), x(22), x(222), y(2)
.
.
.
x(n), x(nn), x(nnn), y(n)


which for each y(i) there is three corresponding x(i), x(ii), x(iii). Indeed the value of the y(i) depends on the values of x(i), x(ii) and x(iii).

In the end, I want to generate a formula like:

 y = f[x1, x2 , x3]

• What have you tried in Mathematica? Do you have an example data set? – JimB Jul 5 '17 at 17:42
• To make a fit you must have a model. If you don't have a model in mind, you might try making and interpolation function. See Interpolation in the Documentation Center. If you do have a model in mind, please edit your question to describe the model. Do not use the comments facility to describe the model. – m_goldberg Jul 5 '17 at 17:49