<s>
A	O
growing	B-Algorithm
self-organizing	I-Algorithm
map	I-Algorithm
(	O
GSOM	B-Algorithm
)	O
is	O
a	O
growing	O
variant	O
of	O
a	O
self-organizing	B-Algorithm
map	I-Algorithm
(	O
SOM	B-Algorithm
)	O
.	O
</s>
<s>
The	O
GSOM	B-Algorithm
was	O
developed	O
to	O
address	O
the	O
issue	O
of	O
identifying	O
a	O
suitable	O
map	O
size	O
in	O
the	O
SOM	B-Algorithm
.	O
</s>
<s>
By	O
using	O
the	O
value	O
called	O
Spread	O
Factor	O
(	O
SF	O
)	O
,	O
the	O
data	O
analyst	O
has	O
the	O
ability	O
to	O
control	O
the	O
growth	O
of	O
the	O
GSOM	B-Algorithm
.	O
</s>
<s>
All	O
the	O
starting	O
nodes	O
of	O
the	O
GSOM	B-Algorithm
are	O
boundary	O
nodes	O
,	O
i.e.	O
</s>
<s>
The	O
figure	O
shows	O
the	O
three	O
possible	O
node	O
growth	O
options	O
for	O
a	O
rectangular	O
GSOM	B-Algorithm
.	O
</s>
<s>
The	O
GSOM	B-Algorithm
process	O
is	O
as	O
follows	O
:	O
</s>
<s>
Determine	O
the	O
weight	O
vector	O
that	O
is	O
closest	O
to	O
the	O
input	O
vector	O
mapped	O
to	O
the	O
current	O
feature	O
map	O
(	O
winner	O
)	O
,	O
using	O
Euclidean	O
distance	O
(	O
similar	O
to	O
the	O
SOM	B-Algorithm
)	O
.	O
</s>
<s>
The	O
neighborhood	O
is	O
a	O
set	O
of	O
neurons	O
around	O
the	O
winner	O
,	O
but	O
in	O
the	O
GSOM	B-Algorithm
the	O
starting	O
neighborhood	O
selected	O
for	O
weight	O
adaptation	O
is	O
smaller	O
compared	O
to	O
the	O
SOM	B-Algorithm
(	O
localized	O
weight	O
adaptation	O
)	O
.	O
</s>
<s>
The	O
decreasing	O
value	O
of	O
in	O
the	O
GSOM	B-Algorithm
depends	O
on	O
the	O
number	O
of	O
nodes	O
existing	O
in	O
the	O
map	O
at	O
time	O
.	O
</s>
<s>
The	O
GSOM	B-Algorithm
can	O
be	O
used	O
for	O
many	O
preprocessing	O
tasks	O
in	O
Data	B-Application
mining	I-Application
,	O
for	O
Nonlinear	B-Algorithm
dimensionality	I-Algorithm
reduction	I-Algorithm
,	O
for	O
approximation	O
of	O
principal	O
curves	O
and	O
manifolds	O
,	O
for	O
clustering	B-Algorithm
and	O
classification	B-General_Concept
.	O
</s>
<s>
It	O
gives	O
often	O
the	O
better	O
representation	O
of	O
the	O
data	O
geometry	O
than	O
the	O
SOM	B-Algorithm
(	O
see	O
the	O
classical	O
benchmark	O
for	O
principal	O
curves	O
on	O
the	O
left	O
)	O
.	O
</s>
