From Wikipedia,
the free encyclopedia.
In
mathematics, a distance
matrix is a
matrix (two-dimensional
array) containing the
distances, taken pairwise, of a
set of points. It is therefore a
symmetric N×N
matrix containing non-negative
reals as elements, given N
points in
Euclidean space. The number of
pairs of points N×(N-1)/2
is the number of independent
elements in the distance matrix.
In
bioinformatics, distances
matrices are used to represent
protein structures in a
coordinate-independent manner, as
well as the pairwise distances
between two sequences in sequence
space. They are used in
structural and
sequential alignment, and for
the determination of protein
structures from
NMR or
X-ray
crystallography.
Sometimes it is more convenient
to express data as a
similarity matrix.
