Exercise 12
Mean of a vector
If we have a vector \(X\) containing \(n\) values, then the mean \(\bar{X}\) is:
\begin{equation} \bar{X} = \frac{1}{n} \sum_{i=1}^{N} \left( X_{i} \right) \end{equation}
In MATLAB, Python (NumPy) and R there are built-in functions for
computing the mean of a vector. Conveniently, in all three languages
the function is called mean().
In MATLAB:
x = [2,1,5,4,8,3,4,3]; mean(x) ans = 3.7500
In Python / NumPy: (started using ipython --pylab)
x = array([2,1,5,4,8,3,4,3], 'float') mean(x) Out[2]: 3.75
In R:
x <- c(2,1,5,4,8,3,4,3) mean(x) [1] 3.75
from scratch
Write a function called mymean() that computes the mean of a list of
numbers. Do it from scratch, in other words don't use the built-in
function mean().
