I'm able to do data bar conditional formatting in Excel 2010, but I can't figure out how to switch the bar axis to make it vertical. Is there any way around this? Can I simulate a vertical histogram with conditional formatting?
Data bars in conditional formatting are Left-Right or Right-Left only. There's no Up-Down or Down-Up option available.
The only way to get a vertical data bar-type look would be to use a formula and change the Fill settings to a gradient, but you don't get enough control over the gradient to differentiate the different values.
Another option is to spark lines. There's a nice example of something that might do what you want here: http://blogs.office.com/b/microsoft-excel/archive/2009/07/22/formatting-sparklines.aspx
You can't change the conditional formatting in Excel to create a column chart instead of a bar chart. This conditional formatting isn't creating a true Chart object in Excel, so you don't have the same flexibility in modifying its appearance.
Instead, you can create a
EDIT: Based upon your notes, and borrowing from @Rhys Gibson, here's a solution using sparklines (which are available in Excel 2010, or add-ins pre-Excel 2010). I've included both the conditional formating bar charts (nearly impossible to make sense of), and their sparkline equivalents.
EDIT: One other point that may seem relatively minor, a Histogram is not a Column (or Bar) chart. They are distinctly (if subtly) different chart types and the terminology shouldn't be interchanged. For a great description of the difference, check out Naomi Robbins' A Histogram is not a Bar Chart
I was interested in something similar and was able to achieve it. Though I didn't use conditional formatting, I think this example will show you how to achieve what you want.
That's achieves the outcome but to make it look nice you'll want to center the cells and adjust cell width and height.
It should look like this:
If you don't like the spaces between the lines switch the font to playbill and you'll see a normal bar graph with no spaces.
This does what you want without conditional formatting. You may want to add some conditional formatting if you want to vary the color of the bar graphs or something else.