Finding Mean Squared Error?
<p>I have produced a linear data set and have used <code>lm()</code> to fit a model to that dataset. I am now trying to find the MSE using <code>mse()</code></p>

<p>I know the formula for MSE but I'm trying to use this function. What would be the proper way to do so? I have looked at the documentation, but I'm either dumb or it's just worded for people who actually know what they're doing.</p>

<pre><code>library(hydroGOF)

x.linear &lt;- seq(0, 200, by=1) # x data
error.linear &lt;- rnorm(n=length(x.linear), mean=0, sd=1) # Error (0, 1)
y.linear &lt;- x.linear + error.linear  # y data

training.data &lt;- data.frame(x.linear, y.linear)
training.model &lt;- lm(training.data)
training.mse &lt;- mse(training.model, training.data)

plot(training.data)
</code></pre>

<p><code>mse()</code> needs two data frames. I'm not sure how to get a data frame out of <code>lm()</code>. Am I even on the right track to finding a proper MSE for my data?</p>