<s>
The	O
fast	B-Algorithm
marching	I-Algorithm
method	I-Algorithm
is	O
a	O
numerical	B-Algorithm
method	I-Algorithm
created	O
by	O
James	O
Sethian	O
for	O
solving	O
boundary	O
value	O
problems	O
of	O
the	O
Eikonal	O
equation	O
:	O
</s>
<s>
The	O
fast	B-Algorithm
marching	I-Algorithm
method	I-Algorithm
takes	O
advantage	O
of	O
this	O
optimal	O
control	O
interpretation	O
of	O
the	O
problem	O
in	O
order	O
to	O
build	O
a	O
solution	O
outwards	O
starting	O
from	O
the	O
"	O
known	O
information	O
"	O
,	O
i.e.	O
</s>
<s>
The	O
algorithm	O
is	O
similar	O
to	O
Dijkstra	B-Algorithm
's	I-Algorithm
algorithm	I-Algorithm
and	O
uses	O
the	O
fact	O
that	O
information	O
only	O
flows	O
outward	O
from	O
the	O
seeding	O
area	O
.	O
</s>
<s>
This	O
problem	O
is	O
a	O
special	O
case	O
of	O
level-set	B-Algorithm
methods	I-Algorithm
.	O
</s>
<s>
The	O
algorithm	O
works	O
just	O
like	O
Dijkstra	B-Algorithm
's	I-Algorithm
algorithm	I-Algorithm
but	O
differs	O
in	O
how	O
the	O
nodes	O
 '	O
values	O
are	O
calculated	O
.	O
</s>
<s>
In	O
Dijkstra	B-Algorithm
's	I-Algorithm
algorithm	I-Algorithm
,	O
a	O
node	O
's	O
value	O
is	O
calculated	O
using	O
a	O
single	O
one	O
of	O
the	O
neighboring	O
nodes	O
.	O
</s>
