<p>I have tried quite a few symbolic regression implementations, including rgp, gplearn and a Python tool called fast-symbolic-regression. None of these was nearly comparable to Eureqa, a symbolic regression tool that I first used in 2015 and that left the market in 2017.</p>
<p>Recently a new symbolic regression tool called <a href="https://turingbotsoftware.com/" rel="nofollow noreferrer">TuringBot</a> was developed, and it was shown in <a href="https://arxiv.org/abs/2010.11328" rel="nofollow noreferrer">arXiv:2010.11328</a> to be more efficient than Eureqa at finding formulas. So I would recommend TuringBot for symbolic regression in 2020.</p>
How to get the function result from Symbolic Regression with R
<p>First, please excuse my ignorance because I've just started learning R today.</p>

<p>I have a data frame of two variables (x, y) as follows: <code>(1,0), (2,26), (3,88), (4,186), (5,320), (6,490), (7,541)</code>. I want to use Symbolic Regression to find a function <code>f</code> such that <code>y = f(x)</code>.</p>

<p>Following the tutorial <a href="http://rsymbolic.org/projects/rgp/wiki/Symbolic_Regression" rel="noreferrer">here</a>, I can have a plot of <code>f(x)</code>, which is closed to what I expect. However, I don't know how to print out the function <code>f(x)</code>. </p>

<p>I tried with another tool called Eurequa. It is pretty easy to use, and gives me (a lot of) functions. But I can't use a commercial tool for my project. Thank you.</p>

<hr>

<h1>UPDATE</h1>

<p>Here is my code to compute Symbolic Regression and plot the function. I enter the command one by one in R environment.  </p>

<pre><code>x = c (1, 2, 3, 4, 5, 6, 7)
y = c (0, 26, 88, 186, 320, 490, 541)
data1 = data.frame(x,y)
newFuncSet &lt;- functionSet("+","-","*")
result1 &lt;- symbolicRegression(y ~ x, data = data1, functionSet = newFuncSet, stopCondition = makeStepsStopCondition(2000))
plot(data1$y, col=1, type="l"); points(predict(result1, newdata = data1), col=2, type="l")
</code></pre>