<s>
Multiple	B-Algorithm
factor	I-Algorithm
analysis	I-Algorithm
(	O
MFA	O
)	O
is	O
a	O
factorial	O
method	O
devoted	O
to	O
the	O
study	O
of	O
tables	O
in	O
which	O
a	O
group	O
of	O
individuals	O
is	O
described	O
by	O
a	O
set	O
of	O
variables	O
(	O
quantitative	O
and	O
/	O
or	O
qualitative	O
)	O
structured	O
in	O
groups	O
.	O
</s>
<s>
It	O
is	O
a	O
multivariate	B-General_Concept
method	I-General_Concept
from	O
the	O
field	O
of	O
ordination	B-Algorithm
used	O
to	O
simplify	O
multidimensional	B-Algorithm
data	I-Algorithm
structures	O
.	O
</s>
<s>
Principal	B-Application
component	I-Application
analysis	I-Application
(	O
PCA	O
)	O
when	O
variables	O
are	O
quantitative	O
,	O
</s>
<s>
Multiple	B-Algorithm
correspondence	I-Algorithm
analysis	I-Algorithm
(	O
MCA	O
)	O
when	O
variables	O
are	O
qualitative	O
,	O
</s>
<s>
Factor	B-Algorithm
analysis	I-Algorithm
of	I-Algorithm
mixed	I-Algorithm
data	I-Algorithm
(	O
FAMD	O
)	O
when	O
the	O
active	O
variables	O
belong	O
to	O
the	O
two	O
types	O
.	O
</s>
<s>
the	O
principal	B-Application
components	I-Application
)	O
are	O
related	O
to	O
the	O
pedological	O
variables	O
introduced	O
as	O
supplementary	O
.	O
</s>
<s>
the	O
principal	B-Application
components	I-Application
)	O
are	O
then	O
related	O
to	O
the	O
abundance	O
of	O
plants	O
.	O
</s>
<s>
The	O
superimposed	O
representation	O
of	O
the	O
provided	O
by	O
the	O
MFA	O
is	O
similar	O
in	O
its	O
purpose	O
to	O
that	O
provided	O
by	O
the	O
Procrustes	B-Algorithm
analysis	I-Algorithm
.	O
</s>
<s>
This	O
group	O
,	O
consisting	O
of	O
two	O
identical	O
variables	O
,	O
possesses	O
only	O
one	O
principal	B-Application
component	I-Application
(	O
confounded	O
with	O
the	O
variable	O
)	O
.	O
</s>
<s>
So	O
there	O
is	O
uncertainty	O
in	O
the	O
choice	O
of	O
principal	B-Application
components	I-Application
and	O
there	O
is	O
no	O
reason	O
to	O
be	O
interested	O
in	O
one	O
of	O
them	O
in	O
particular	O
.	O
</s>
<s>
Procrustes	B-Algorithm
analysis	I-Algorithm
is	O
compared	O
to	O
the	O
MFA	O
in	O
.	O
</s>
