Compound bar chart - to round or not to round? (percentages)

3vo

New member
Hi guys,

I'm currently drawing a compound bar chart.
As I understand, this is type of bar chart which involves sub data within each grouping. The sub data is incorporated into each of their grouping bar as a percentage out of 100% of that bar. So basically the bar is 100% in total and the sub data is drawn into the bar, as their respective percentage of the bar. (I could of prob explained that a lot better).

Anyway... I've drawn up my chart and worked the percentages of each sub data within each grouping out of a 100%. However for some of the groups, the sub data are NOT integers.

Do I round these figures up to a whole number? or a specific number of dp or sf? What do I do if after rounding the total doesnt add up to 100%?

Or is it better to leave them as they are and try to best incorporate them into the graph?

An example of my data: Imagine a table below (dont know how to do one here)
First number is freq, 2nd is %
Monday | Tuesday |
Red 7 30.'43% 3 18.75%
Blue 10 43.'47% 7 43.75%
Black 6 26.08% 6 36.5%
Totals 23 100% 16 100%

Klaas van Aarsen

MHB Seeker
Staff member
Do I round these figures up to a whole number? or a specific number of dp or sf? What do I do if after rounding the total doesnt add up to 100%?

Or is it better to leave them as they are and try to best incorporate them into the graph?
Hi 3vo!

Yep. Leave them as they are, or round them to some significant number of digits.
Up to you basically. What you think looks best and is most informative.

But if you do round them, don't round up, but round normally.
0.5 goes up, 0.4999 goes down.

And if they don't add up to 100%, don't worry about it.
That's normal - the result of rounding errors.
This is known and accepted.