Euclidean Distance
The Euclidean distance is a classic method to calculate a distance between two (multi-dimensional) points.
\[ED(T_a,\ T_b)=\sum _{i=1} ^n d(p_{ai}, p_{bi})\]Whereas $T$ denotes the trajectory $[p_0, p_i, p_n]$
1 dimension
$d(p,\ q)=|p-q|.$
Or in more generalized form:
$d(p,\ q)=\sqrt {(p-q)^2}.$
2 dimensions
$d(p,\ q)=\sqrt {(q_1-p_1)^2 + (q_2-p_2)^2}.$
n dimensions
$d(p,\ q)=\sqrt {(p_1-q_1)^2 + (p_2-q_2)^2 + … + (p_i-q_i)^2 + … + (p_n-q_n)^2}.$