<s>
A	O
heat	B-Application
map	I-Application
(	O
or	O
heatmap	B-Application
)	O
is	O
a	O
data	B-Application
visualization	I-Application
technique	O
that	O
shows	O
magnitude	O
of	O
a	O
phenomenon	O
as	O
color	O
in	O
two	O
dimensions	O
.	O
</s>
<s>
The	O
variation	O
in	O
color	O
may	O
be	O
by	O
hue	B-Language
or	O
intensity	O
,	O
giving	O
obvious	O
visual	O
cues	O
to	O
the	O
reader	O
about	O
how	O
the	O
phenomenon	O
is	O
clustered	O
or	O
varies	O
over	O
space	O
.	O
</s>
<s>
There	O
are	O
two	O
fundamentally	O
different	O
categories	O
of	O
heat	B-Application
maps	I-Application
:	O
the	O
cluster	O
heat	B-Application
map	I-Application
and	O
the	O
spatial	O
heat	B-Application
map	I-Application
.	O
</s>
<s>
In	O
a	O
cluster	O
heat	B-Application
map	I-Application
,	O
magnitudes	O
are	O
laid	O
out	O
into	O
a	O
matrix	O
of	O
fixed	O
cell	O
size	O
whose	O
rows	O
and	O
columns	O
are	O
discrete	O
phenomena	O
and	O
categories	O
,	O
and	O
the	O
sorting	O
of	O
rows	O
and	O
columns	O
is	O
intentional	O
and	O
somewhat	O
arbitrary	O
,	O
with	O
the	O
goal	O
of	O
suggesting	O
clusters	O
or	O
portraying	O
them	O
as	O
discovered	O
via	O
statistical	O
analysis	O
.	O
</s>
<s>
By	O
contrast	O
,	O
the	O
position	O
of	O
a	O
magnitude	O
in	O
a	O
spatial	O
heat	B-Application
map	I-Application
is	O
forced	O
by	O
the	O
location	O
of	O
the	O
magnitude	O
in	O
that	O
space	O
,	O
and	O
there	O
is	O
no	O
notion	O
of	O
cells	O
;	O
the	O
phenomenon	O
is	O
considered	O
to	O
vary	O
continuously	O
.	O
</s>
<s>
"	O
Heat	B-Application
map	I-Application
"	O
is	O
a	O
relatively	O
new	O
term	O
,	O
but	O
the	O
practice	O
of	O
shading	O
matrices	O
has	O
existed	O
for	O
over	O
a	O
century	O
.	O
</s>
<s>
Heat	B-Application
maps	I-Application
originated	O
in	O
2D	O
displays	O
of	O
the	O
values	O
in	O
a	O
data	O
matrix	O
.	O
</s>
<s>
Sneath	O
(	O
1957	O
)	O
displayed	O
the	O
results	O
of	O
a	O
cluster	B-Algorithm
analysis	I-Algorithm
by	O
permuting	O
the	O
rows	O
and	O
the	O
columns	O
of	O
a	O
matrix	O
to	O
place	O
similar	O
values	O
near	O
each	O
other	O
according	O
to	O
the	O
clustering	O
.	O
</s>
<s>
Jacques	O
Bertin	O
used	O
a	O
similar	O
representation	O
to	O
display	O
data	O
that	O
conformed	O
to	O
a	O
Guttman	B-General_Concept
scale	I-General_Concept
.	O
</s>
<s>
Leland	O
Wilkinson	O
developed	O
the	O
first	O
computer	O
program	O
in	O
1994	O
(	O
SYSTAT	B-Language
)	O
to	O
produce	O
cluster	O
heat	B-Application
maps	I-Application
with	O
high-resolution	O
color	O
graphics	O
.	O
</s>
<s>
display	O
shown	O
in	O
the	O
figure	O
is	O
a	O
replication	O
of	O
the	O
earlier	O
SYSTAT	B-Language
design	O
.	O
</s>
<s>
Software	O
designer	O
Cormac	O
Kinney	O
trademarked	O
the	O
term	O
'	O
heat	B-Application
map	I-Application
 '	O
in	O
1991	O
to	O
describe	O
a	O
2D	O
display	O
depicting	O
financial	O
market	O
information	O
.	O
</s>
<s>
There	O
are	O
two	O
main	O
type	O
of	O
heat	B-Application
maps	I-Application
:	O
spatial	O
,	O
and	O
grid	O
.	O
</s>
<s>
A	O
spatial	O
heat	B-Application
map	I-Application
displays	O
the	O
magnitude	O
of	O
a	O
spatial	O
phenomena	O
as	O
color	O
,	O
usually	O
cast	O
over	O
a	O
map	O
.	O
</s>
<s>
In	O
the	O
image	O
labeled	O
“	O
Spatial	O
Heat	B-Application
Map	I-Application
Example	O
,	O
”	O
temperature	O
is	O
displayed	O
by	O
color	O
range	O
across	O
a	O
map	O
of	O
the	O
world	O
.	O
</s>
<s>
A	O
grid	O
heat	B-Application
map	I-Application
displays	O
magnitude	O
as	O
color	O
in	O
a	O
two-dimensional	O
matrix	O
,	O
with	O
each	O
dimension	O
representing	O
a	O
category	O
of	O
trait	O
and	O
the	O
color	O
representing	O
the	O
magnitude	O
of	O
some	O
measurement	O
on	O
the	O
combined	O
traits	O
from	O
each	O
of	O
the	O
two	O
categories	O
.	O
</s>
<s>
This	O
heat	B-Application
map	I-Application
would	O
show	O
how	O
temperature	O
changed	O
over	O
the	O
years	O
in	O
each	O
month	O
.	O
</s>
<s>
Grid	O
heat	B-Application
maps	I-Application
are	O
further	O
categorized	O
into	O
two	O
different	O
types	O
of	O
matrices	O
:	O
clustered	O
,	O
and	O
correlogram	O
.	O
</s>
<s>
Clustered	O
heat	B-Application
map	I-Application
:	O
The	O
example	O
of	O
the	O
monthly	O
temperature	O
by	O
year	O
is	O
a	O
clustered	O
heat	B-Application
map	I-Application
.	O
</s>
<s>
Correlogram	O
:	O
A	O
correlogram	O
is	O
a	O
clustered	O
heat	B-Application
map	I-Application
that	O
has	O
the	O
same	O
trait	O
for	O
each	O
axis	O
in	O
order	O
to	O
display	O
how	O
the	O
traits	O
in	O
the	O
set	O
of	O
traits	O
interact	O
with	O
each	O
other	O
.	O
</s>
<s>
Heat	B-Application
maps	I-Application
have	O
a	O
wide	O
range	O
of	O
possibilities	O
amongst	O
applications	O
due	O
to	O
their	O
ability	O
to	O
simplify	O
data	O
and	O
make	O
for	O
visually	O
appealing	O
to	O
read	O
data	O
analysis	O
.	O
</s>
<s>
Many	O
applications	O
using	O
different	O
types	O
of	O
heat	B-Application
maps	I-Application
are	O
listed	O
below	O
.	O
</s>
<s>
Business	O
Analysis	O
:	O
Heat	B-Application
maps	I-Application
are	O
used	O
in	O
business	O
analytics	O
to	O
give	O
a	O
visual	O
representation	O
about	O
a	O
company	O
’s	O
current	O
functioning	O
,	O
performance	O
,	O
and	O
the	O
need	O
for	O
improvements	O
.	O
</s>
<s>
Heat	B-Application
maps	I-Application
are	O
a	O
way	O
to	O
analyze	O
a	O
company	O
’s	O
existing	O
data	O
and	O
update	O
it	O
to	O
reflect	O
growth	O
and	O
other	O
specific	O
efforts	O
.	O
</s>
<s>
Heat	B-Application
maps	I-Application
visually	O
appeal	O
to	O
team	O
members	O
and	O
clients	O
of	O
the	O
business	O
or	O
company	O
.	O
</s>
<s>
Websites	O
:	O
There	O
are	O
many	O
different	O
ways	O
heat	B-Application
maps	I-Application
are	O
used	O
within	O
websites	O
to	O
determine	O
a	O
visiting	O
users	O
actions	O
.	O
</s>
<s>
Typically	O
,	O
there	O
are	O
multiple	O
heat	B-Application
maps	I-Application
used	O
together	O
to	O
determine	O
insight	O
to	O
a	O
website	O
on	O
what	O
are	O
the	O
best	O
and	O
worst	O
performing	O
elements	O
on	O
the	O
page	O
.	O
</s>
<s>
Some	O
specific	O
heat	B-Application
maps	I-Application
used	O
for	O
website	O
analysis	O
are	O
listed	O
below	O
.	O
</s>
<s>
Mouse	O
Tracking	O
:	O
Mouse	O
tracking	O
heat	B-Application
maps	I-Application
or	O
hover	O
maps	O
,	O
are	O
used	O
to	O
visualize	O
where	O
the	O
user	O
of	O
the	O
site	O
hovers	O
their	O
cursor	O
.	O
</s>
<s>
Eye	O
tracking	O
:	O
Eye	O
tracking	O
heat	B-Application
maps	I-Application
measure	O
the	O
eye	O
position	O
of	O
the	O
website	O
's	O
users	O
and	O
gathers	O
measurements	O
such	O
as	O
eye	O
fixation	O
volume	O
,	O
eye	O
fixation	O
duration	O
,	O
and	O
areas	O
of	O
interest	O
.	O
</s>
<s>
Click	O
Tracking	O
:	O
Click	O
tracking	O
heat	B-Application
maps	I-Application
or	O
touch	O
maps	O
,	O
are	O
similar	O
to	O
mouse	O
tracking	O
heat	B-Application
maps	I-Application
,	O
but	O
instead	O
of	O
hover	O
actions	O
,	O
these	O
types	O
of	O
heat	B-Application
maps	I-Application
help	O
visualize	O
the	O
users	O
click	O
actions	O
.	O
</s>
<s>
Click	O
tracking	O
heat	B-Application
maps	I-Application
not	O
only	O
allow	O
for	O
visual	O
cues	O
on	O
clickable	O
components	O
on	O
a	O
webpage	O
,	O
such	O
as	O
buttons	O
or	O
dropdown	O
menus	O
,	O
but	O
these	O
heat	B-Application
maps	I-Application
also	O
allow	O
for	O
tracking	O
on	O
non-clickable	O
objects	O
anywhere	O
on	O
the	O
page	O
.	O
</s>
<s>
AI-Generation	O
Attention	O
:	O
AI-generated	O
attention	O
heat	B-Application
maps	I-Application
help	O
visualize	O
where	O
the	O
visiting	O
user	O
’s	O
attention	O
will	O
go	O
on	O
a	O
certain	O
section	O
of	O
a	O
webpage	O
.	O
</s>
<s>
These	O
types	O
of	O
heat	B-Application
maps	I-Application
are	O
implemented	O
using	O
a	O
created	O
software	O
algorithm	O
to	O
determine	O
and	O
predict	O
the	O
attention	O
actions	O
of	O
the	O
user	O
.	O
</s>
<s>
Scroll	O
Tracking	O
:	O
Scroll	O
tracking	O
heat	B-Application
maps	I-Application
are	O
used	O
to	O
represent	O
the	O
scrolling	O
behavior	O
of	O
the	O
website	O
’s	O
users	O
.	O
</s>
<s>
Exploratory	B-General_Concept
Data	I-General_Concept
Analysis	I-General_Concept
:	O
Working	O
with	O
small	O
and	O
large	O
data	O
sets	O
,	O
data	O
scientists	O
and	O
data	O
analysts	O
look	O
at	O
and	O
determine	O
essential	O
relationships	O
and	O
characteristics	O
amongst	O
different	O
points	O
in	O
a	O
data	O
set	O
as	O
well	O
as	O
features	O
of	O
those	O
data	O
points	O
.	O
</s>
<s>
The	O
use	O
of	O
heat	B-Application
maps	I-Application
make	O
for	O
a	O
visually	O
easy	O
way	O
to	O
summarize	O
findings	O
and	O
main	O
components	O
.	O
</s>
<s>
There	O
are	O
other	O
ways	O
to	O
represent	O
data	O
,	O
however	O
heat	B-Application
maps	I-Application
can	O
visualize	O
these	O
data	O
points	O
and	O
their	O
relationships	O
in	O
a	O
high	O
dimensional	O
space	O
without	O
becoming	O
too	O
compact	O
and	O
visually	O
unappealing	O
.	O
</s>
<s>
Heat	B-Application
maps	I-Application
in	O
data	O
analysis	O
,	O
allow	O
for	O
specific	O
variables	O
of	O
rows	O
and/or	O
columns	O
on	O
the	O
axes	O
and	O
even	O
on	O
the	O
diagonal	O
.	O
</s>
<s>
Biology	O
:	O
In	O
the	O
biological	O
field	O
,	O
heat	B-Application
maps	I-Application
are	O
used	O
to	O
visually	O
represent	O
large	O
and	O
small	O
sets	O
of	O
data	O
.	O
</s>
<s>
Working	O
with	O
these	O
sets	O
of	O
data	O
,	O
data	O
scientists	O
in	O
bioinformatics	O
,	O
focus	O
on	O
different	O
concepts	O
,	O
some	O
of	O
which	O
being	O
community	O
detection	O
,	O
association	O
and	O
correlation	O
,	O
and	O
the	O
concept	O
of	O
centrality	O
,	O
where	O
heat	B-Application
maps	I-Application
are	O
a	O
compelling	O
way	O
to	O
visually	O
summarize	O
results	O
and	O
to	O
share	O
amongst	O
other	O
professions	O
not	O
in	O
the	O
field	O
of	O
biology	O
or	O
bioinformatics	O
.	O
</s>
<s>
The	O
two	O
heat	B-Application
maps	I-Application
to	O
the	O
right	O
,	O
labeled	O
“	O
Data	O
Analysis	O
Heat	B-Application
Map	I-Application
Example	O
,	O
”	O
show	O
different	O
ways	O
in	O
which	O
one	O
may	O
present	O
genomic	O
data	O
over	O
a	O
specific	O
region	O
(	O
Hist1	O
region	O
)	O
to	O
someone	O
outside	O
the	O
field	O
of	O
biology	O
so	O
they	O
have	O
a	O
better	O
understanding	O
of	O
the	O
general	O
concept	O
a	O
biologist	O
or	O
data	O
scientist	O
are	O
trying	O
to	O
present	O
.	O
</s>
<s>
Heat	B-Application
maps	I-Application
are	O
able	O
to	O
remove	O
the	O
tedious	O
process	O
and	O
enable	O
the	O
user	O
to	O
visualize	O
data	O
points	O
and	O
compare	O
amongst	O
the	O
different	O
performers	O
.	O
</s>
<s>
Geographical	O
Visualization	O
:	O
Heat	B-Application
maps	I-Application
are	O
used	O
to	O
visualize	O
and	O
display	O
a	O
geographic	O
distribution	O
of	O
data	O
.	O
</s>
<s>
Heat	B-Application
maps	I-Application
represent	O
different	O
densities	O
of	O
data	O
points	O
on	O
a	O
geographical	O
map	O
to	O
help	O
users	O
see	O
the	O
intensities	O
of	O
certain	O
phenomena	O
and	O
to	O
show	O
items	O
of	O
most	O
or	O
least	O
importance	O
.	O
</s>
<s>
Usually	O
,	O
heat	B-Application
maps	I-Application
used	O
in	O
geographical	O
visualization	O
are	O
mistaken	O
for	O
Choropleth	O
maps	O
,	O
but	O
the	O
difference	O
comes	O
with	O
how	O
certain	O
data	O
is	O
presented	O
which	O
differentiate	O
the	O
two	O
.	O
</s>
<s>
Sports	O
:	O
Heat	B-Application
maps	I-Application
can	O
be	O
used	O
in	O
many	O
sports	O
and	O
can	O
influence	O
manager	O
’s	O
and/or	O
coaches	O
decisions	O
based	O
on	O
high	O
and	O
low	O
densities	O
of	O
data	O
displayed	O
.	O
</s>
<s>
Heat	B-Application
maps	I-Application
also	O
visualize	O
comparisons	O
and	O
relationships	O
amongst	O
different	O
teams	O
in	O
the	O
same	O
sport	O
or	O
between	O
different	O
sports	O
all	O
together	O
.	O
</s>
<s>
Many	O
different	O
color	O
schemes	O
can	O
be	O
used	O
to	O
illustrate	O
the	O
heat	B-Application
map	I-Application
,	O
with	O
perceptual	O
advantages	O
and	O
disadvantages	O
for	O
each	O
.	O
</s>
<s>
The	O
more	O
colors	O
used	O
in	O
a	O
visualization	O
the	O
more	O
values	O
begin	O
to	O
bleed	O
together	O
and	O
color	O
lacks	O
the	O
natural	O
perceptual	O
ordering	O
found	O
in	O
grayscale	O
or	O
blackbody	O
spectrum	O
colormaps	B-Application
.	O
</s>
<s>
Common	O
colormaps	B-Application
(	O
like	O
the	O
"	O
jet	O
"	O
colormap	B-Application
used	O
as	O
the	O
default	O
in	O
many	O
visualization	O
software	O
packages	O
)	O
have	O
uncontrolled	O
changes	O
in	O
luminance	O
that	O
prevent	O
meaningful	O
conversion	O
to	O
grayscale	O
for	O
display	O
or	O
printing	O
.	O
</s>
<s>
Several	O
heat	B-Application
map	I-Application
software	O
implementations	O
are	O
freely	O
available	O
:	O
</s>
<s>
R	B-Language
,	O
a	O
free	O
software	O
environment	O
for	O
statistical	O
computing	O
and	O
graphics	O
,	O
contains	O
several	O
functions	O
to	O
trace	O
heat	B-Application
maps	I-Application
,	O
</s>
<s>
Gnuplot	B-Application
,	O
a	O
universal	O
and	O
free	O
command-line	O
plotting	O
program	O
,	O
can	O
trace	O
2D	O
and	O
3D	O
heat	B-Application
maps	I-Application
.	O
</s>
<s>
Google	B-Application
Fusion	I-Application
Tables	I-Application
can	O
generate	O
a	O
heat	B-Application
map	I-Application
from	O
a	O
Google	B-Language
Sheets	I-Language
spreadsheet	O
limited	O
to	O
1000	O
points	O
of	O
geographic	O
data	O
.	O
</s>
<s>
Openlayers3	O
can	O
render	O
a	O
heat	B-Application
map	I-Application
layer	O
of	O
a	O
selected	O
property	O
of	O
all	O
geographic	O
features	O
in	O
a	O
vector	O
layer	O
.	O
</s>
<s>
D3.js	B-Language
,	O
AnyChart	B-Application
and	O
Highcharts	B-Application
are	O
JavaScript	B-Language
libraries	I-Language
for	O
data	B-Application
visualization	I-Application
that	O
provide	O
the	O
ability	O
to	O
create	O
interactive	O
heat	B-Application
map	I-Application
charts	O
,	O
from	O
basic	O
to	O
highly	O
customized	O
,	O
as	O
part	O
of	O
their	O
solutions	O
.	O
</s>
<s>
Choropleth	O
maps	O
and	O
heat	B-Application
maps	I-Application
are	O
often	O
used	O
in	O
place	O
of	O
one	O
another	O
incorrectly	O
when	O
referring	O
to	O
data	O
visualized	O
geographically	O
.	O
</s>
<s>
If	O
the	O
data	O
were	O
collected	O
and	O
aggregated	O
using	O
irregular	O
boundaries	O
,	O
such	O
as	O
administrative	O
units	O
,	O
then	O
a	O
heat	B-Application
map	I-Application
displaying	O
that	O
data	O
will	O
be	O
the	O
same	O
as	O
a	O
choropleth	O
map	O
,	O
encouraging	O
confusion	O
about	O
how	O
the	O
two	O
differ	O
.	O
</s>
<s>
Similarly	O
,	O
heat	B-Application
maps	I-Application
may	O
also	O
visualize	O
data	O
over	O
a	O
geographic	O
region	O
.	O
</s>
<s>
However	O
,	O
unlike	O
choropleth	O
maps	O
,	O
heat	B-Application
maps	I-Application
show	O
the	O
proportion	O
of	O
a	O
variable	O
over	O
an	O
arbitrary	O
,	O
but	O
usually	O
small	O
grid	O
size	O
,	O
independent	O
of	O
geographic	O
boundaries	O
.	O
</s>
<s>
The	O
figure	O
on	O
the	O
right	O
displaying	O
a	O
heat	B-Application
map	I-Application
of	O
world	O
population	O
is	O
an	O
example	O
.	O
</s>
<s>
Some	O
heat	B-Application
maps	I-Application
that	O
are	O
created	O
using	O
approximated	O
regional	O
data	O
may	O
show	O
familiar	O
geographic	O
borders	O
in	O
the	O
visualization	O
where	O
none	O
really	O
exist	O
.	O
</s>
<s>
The	O
figure	O
on	O
the	O
right	O
displaying	O
a	O
heat	B-Application
map	I-Application
of	O
world	O
population	O
also	O
contains	O
this	O
occurrence	O
.	O
</s>
