inspired by your request I implemented a tabluar heat map in Excel, similar to the one in Stephen Few’s article. I did it with Excel 2003, so a small vba-routine is necessary and you would have to enable macros when opening the file.

Unfortunately I do not have a website or blog of my own where I could post it for download. And I don’t want to bother Chandoo again…

So: if you are interested, send me an email to

trm001 (at) online (dot) de

and I will send you the file.

In terms of heatmaps, I was think more of the tabular variety, as described by Perceptual Edge (rules for using color):

http://www.perceptualedge.com/articles/visual_business_intelligence/rules_for_using_color.pdf

I find the version without the data the best!

The cone is especially bad: the conic shape of the data points de-emphasizes the higher values. But I consider Excel’s cones, pyramids, and cylinders to be merely the ugly inbred cousins of the 3D bar and column type charts.

I played with the treemapper a bit, but I really have no projects which have a need for that kind of visualization. Personally I don’t that that treemaps are as wonderful a visualization medium as the hype would indicate. And I think the concept is still not understood across the types of clients I have (scientists, enigneers, financiers, all smart people).

They can be useful, sure: I saw a nice example that broke down the contents and directory structure of a hard drive. But it’s based on areas, with both rectangle positions and colors applied semi-arbitrarily.

Jon, ever tried this TreeMapper add-in for Excel? http://research.microsoft.com/research/downloads/Details/3f3ed95e-26d8-4616-a06c-b609df29756f/Details.aspx

I’ve described a method for doing this here.

with regards to your heat map request:

Actually there is already a post on Chandoo’s blog with a heat map in Excel 2003:

http://chandoo.org/wp/2008/08/12/olympic-medals-excel-chart-improved/

The idea and the vba-code have been taken from Tushar Mehta’s website:

http://www.tushar-mehta.com/excel/charts/0301-dashboard-conditional%20shape%20colors.htm

The map on Chandoo’s post is a world map, but you could easily replace the shapes of the countries by simple rectangles and apply Tushar’s idea to that as well.

Conditional formatting of cells is another option, but – as you mentioned – Excel 2003 is limited to 3 conditions, i.e. 4 colors and that is definitely not enough for a serious heat map. So you would have to use vba again to change the fill colors of the cells. I never did, but I think this shouldn’t be too difficult.

I wouldn’t want to see some of these types go, either. It would be nice if they were de-emphasized, and if there were some kind of smart system for helping users select a chart type. Something like a mature version of Microsoft Lab’s Chart Advisor.

A universal charting engine, like R but with a less steep learning curve, would be nice.

I wouldn’t say Excel has crippled the makers of heat maps, but I will point out that Excel makes it easier sometimes to do the wrong thing graphically. Using more typical heat map data, and a less garish color scheme, would produce a serviceable heat map.

James -

In Excel 2003 you could use VBA conditional formatting to create more colors than the built-in three formats for conditional formatting. You would use an approach not unlike the VBA Chart Conditional Formatting examples on this blog:

VBA Conditional Formatting of Charts by Series Name
VBA Conditional Formatting of Charts by Value
VBA Conditional Formatting of Charts by Category Label