A while ago (well more than 3 years ago), I wrote about an array formula based technique to check if a list of values have any duplicates in them.
Today, lets learn a simpler formula to check if a list has duplicate numbers.
Assuming you have some numbers in a range B4:B10 as shown below,
You can use COUNTIF & MODE formulas to check if the list has any duplicates, like this:
=IF(COUNTIF($B$4:$B$10,MODE($B$4:$B$10))>1, "List has duplicates", "No duplicates")
How does it work?
MODE formula gives us the most frequently occurring number in a list. Then, we use COUNTIF to see how many times this number occurs in a list.
In a list with no duplicates mode value occurs only 1 time. If a list has duplicate numbers, then count of mode would be more than 1. That is what the IF formula checks for and then prints appropriate message.
See this example:
[Embedded Excel, if you can not see it, click here]
Play with below embedded Excel file to understand the technique. You can modify numbers or formula.
Or Download this Example
Click here to download the example workbook and play with it.
How do you check if a list has duplicates?
For text values, I use the array formula technique described here. For numeric values, I prefer MODE + COUNTIF combination because it is easy to write & explain.
What about you? How do you check if a list has duplicates? Which formulas do you use? Please share your techniques using comments.
More on Duplicates & Unique values
If we analyze the time an analyst spends on various things, we would realize,
- 30% of time cleaning data (removing duplicates etc.)
- 30% of time actual analysis
- 30% of time drinking coffee
- 10% of time actual presentation
On a more serious note, if you want to learn various techniques to deal with duplicate values, read on:
- Extracting unique values from a list in Excel using formulas
- Extracting unique values from a list using Pivot tables
- Count the number of values in a list (excluding duplicates)
- Quickly compare 2 lists and check for duplicates
- Removing duplicate values quickly
- Avoiding duplicate data entry using Data Validation
14 Responses to “Group Smaller Slices in Pie Charts to Improve Readability”
I think the virtue of pie charts is precisely that they are difficult to decode. In many contexts, you have to release information but you don't want the relationship between values to jump at your reader. That's when pie charts are most useful.
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Chandoo,
millions of ants cannot be mistaken.....There should be a reason why everybody continues using Pie charts, despite what gurus like you or Jon and others say.
one reason could be because we are just used to, so that's what we need to change, the "comfort zone"...
i absolutely agree, since I've been "converted", I just find out that bar charts are clearer, and nicer to the view...
Regards,
Martin
[...] says we can Group Smaller Slices in Pie Charts to Improve Readability. Such a pie has too many labels to fit into a tight space, so you need ro move the labels around [...]
Chandoo -
You ask "Can I use an alternative to pie chart?"
I answer in You Say “Pie”, I Say “Bar”.
This visualization was created because it was easy to print before computers. In this day and age, it should not exist.
I think the 100% Bar Chart is just as useless/unreadable as Pies - we should rename them something like Mama's Strudel Charts - how big a slice would you like, Dear?
My money's with Jon on this topic.
The primary function of any pie chart with more than 2 or 3 data points is to obfuscate. But maybe that is the main purpose, as @Jerome suggests...
@Jerome.. Good point. Also sometimes, there is just no relationship at all.
@Martin... Organized religion is finding it tough to get converts even after 2000+ years of struggle. Jon, Stephen, countless others (and me) are a small army, it would take atleast 5000 more years before pie charts vanish... patience and good to have you here 🙂
@Jon .. very well done sir, very well done.
good points every one...
I've got to throw my vote into Jon's camp (which is also Stephen Few's camp) -- bars just tend to work better. One observation about when we say "what people are used to." There are two distinct groups here (depending on the situation, a person can fall in either one): the person who *creates* the chart and the person who *consumes* the chart. Granted, the consumers are "used to" pie charts. But, it's not like a bar chart is something they would struggle to understand or that would require explanation (like sparklines and bullet graphs). Chart consumers are "used to" consuming whatever is put in front of them. Chart creators, on the other hand, may be "used to" creating pie charts, but that isn't an excuse for them to continue to do so -- many people are used to driving without a seatbelt, leaving lights on in their house needlessly, and forwarding not-all-that-funny anecdotes via email. That doesn't mean the practice shouldn't be discouraged!
[...] example that Chandoo used recently is counting uses of words. Clearly, there are other meanings of “bar” (take bar mitzvah or bar none, for [...]
[…] Grouping smaller slices in pie chart […]
Good article. Is it possible to do that with line charts?
Hi,
Is this available in excel 2013?