Smoothness of discrete data
Solution 1:
The term you're looking for is "variance." When you look at the data, you fit a curve to it. The curve is smooth, but it's the same curve for both data points. The difference is how much the data varies form the curve, usually measured by $\frac{1}{n}\sum (f(x)-x)^2$ where $f(x)$ is the equation of the curve. The square root of this quantity is known as the "standard deviation"
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