the.com/heatmap
a chart that gossips in color so your eyes don't have to read the spreadsheet.
means a data visualization that uses color intensity instead of numbers to show where values are high or low across a grid.
from the term traces to 1991, coined by software designer cormac kinney for a financial visualization tool tracking market data in real time, though the underlying idea of shading matrices by value goes back to 19th-century statistical graphics.
first use1991, wall street trading floors
web versionclick-tracking heatmaps born early 2000s
color trapred-green ones are invisible to colorblind users
underlying mathjust a matrix wearing a costume
for instance
nba shot charts — teams map every attempt to find cold zones on the floor
weather radar maps — noaa colors rainfall intensity green to red nationwide
github contribution graph — green squares shame or praise your commit habits daily
crazy egg clicks — marketers watch where visitors actually tap since 2006