<s>
A	O
bar	B-Application
chart	I-Application
or	O
bar	B-Application
graph	I-Application
is	O
a	O
chart	O
or	O
graph	O
that	O
presents	O
categorical	O
data	O
with	O
rectangular	O
bars	O
with	O
heights	O
or	O
lengths	O
proportional	O
to	O
the	O
values	O
that	O
they	O
represent	O
.	O
</s>
<s>
A	O
vertical	O
bar	B-Application
chart	I-Application
is	O
sometimes	O
called	O
a	O
column	B-Application
chart	I-Application
.	O
</s>
<s>
A	O
bar	B-Application
graph	I-Application
shows	O
comparisons	O
among	O
discrete	O
categories	O
.	O
</s>
<s>
Some	O
bar	B-Application
graphs	I-Application
present	O
bars	O
clustered	O
in	O
groups	O
of	O
more	O
than	O
one	O
,	O
showing	O
the	O
values	O
of	O
more	O
than	O
one	O
measured	O
variable	O
.	O
</s>
<s>
Many	O
sources	O
consider	O
William	O
Playfair	O
(	O
1759-1824	O
)	O
to	O
have	O
invented	O
the	O
bar	B-Application
chart	I-Application
and	O
the	O
Exports	O
and	O
Imports	O
of	O
Scotland	O
to	O
and	O
from	O
different	O
parts	O
for	O
one	O
Year	O
from	O
Christmas	O
1780	O
to	O
Christmas	O
1781	O
graph	O
from	O
his	O
The	O
Commercial	O
and	O
Political	O
Atlas	O
to	O
be	O
the	O
first	O
bar	B-Application
chart	I-Application
in	O
history	O
.	O
</s>
<s>
Diagrams	O
of	O
the	O
velocity	O
of	O
a	O
constantly	O
accelerating	O
object	O
against	O
time	O
published	O
in	O
The	O
Latitude	O
of	O
Forms	O
(	O
attributed	O
to	O
Jacobus	O
de	O
Sancto	O
Martino	O
or	O
,	O
perhaps	O
,	O
to	O
Nicole	O
Oresme	O
)	O
about	O
300	O
years	O
before	O
can	O
be	O
interpreted	O
as	O
"	O
proto	O
bar	B-Application
charts	I-Application
"	O
.	O
</s>
<s>
In	O
a	O
column	O
(	O
vertical	O
)	O
bar	B-Application
chart	I-Application
,	O
categories	O
appear	O
along	O
the	O
horizontal	O
axis	O
and	O
the	O
height	O
of	O
the	O
bar	O
corresponds	O
to	O
the	O
value	O
of	O
each	O
category	O
.	O
</s>
<s>
Bar	B-Application
charts	I-Application
have	O
a	O
discrete	O
domain	O
of	O
categories	O
,	O
and	O
are	O
usually	O
scaled	O
so	O
that	O
all	O
the	O
data	O
can	O
fit	O
on	O
the	O
chart	O
.	O
</s>
<s>
Bar	B-Application
charts	I-Application
arranged	O
from	O
highest	O
to	O
lowest	O
incidence	O
are	O
called	O
Pareto	O
charts	O
.	O
</s>
<s>
Bar	B-Application
graphs	I-Application
can	O
also	O
be	O
used	O
for	O
more	O
complex	O
comparisons	O
of	O
data	O
with	O
grouped	O
(	O
or	O
"	O
clustered	O
"	O
)	O
bar	B-Application
charts	I-Application
,	O
and	O
stacked	O
bar	B-Application
charts	I-Application
.	O
</s>
<s>
In	O
grouped	O
(	O
clustered	O
)	O
bar	B-Application
charts	I-Application
,	O
for	O
each	O
categorical	O
group	O
there	O
are	O
two	O
or	O
more	O
bars	O
color-coded	O
to	O
represent	O
a	O
particular	O
grouping	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
business	O
owner	O
with	O
two	O
stores	O
might	O
make	O
a	O
grouped	O
bar	B-Application
chart	I-Application
with	O
different	O
colored	O
bars	O
to	O
represent	O
each	O
store	O
:	O
the	O
horizontal	O
axis	O
would	O
show	O
the	O
months	O
of	O
the	O
year	O
and	O
the	O
vertical	O
axis	O
would	O
show	O
revenue	O
.	O
</s>
<s>
Alternatively	O
,	O
a	O
stacked	O
bar	B-Application
chart	I-Application
stacks	O
bars	O
on	O
top	O
of	O
each	O
other	O
so	O
that	O
the	O
height	O
of	O
the	O
resulting	O
stack	O
shows	O
the	O
combined	O
result	O
.	O
</s>
<s>
Stacked	O
bar	B-Application
charts	I-Application
are	O
not	O
suited	O
to	O
data	O
sets	O
having	O
both	O
positive	O
and	O
negative	O
values	O
.	O
</s>
<s>
Grouped	O
bar	B-Application
charts	I-Application
usually	O
present	O
the	O
information	O
in	O
the	O
same	O
order	O
in	O
each	O
grouping	O
.	O
</s>
<s>
Stacked	O
bar	B-Application
charts	I-Application
present	O
the	O
information	O
in	O
the	O
same	O
sequence	O
on	O
each	O
bar	O
.	O
</s>
