Often I wish Microsoft had spent the effort and time on a data genie (and a set of powerful formulas) that can automate common data cleanup tasks like extracting duplicates, makings lists unique, find missing items, remove spaces etc. Alas, instead they have provided features like clippy which are intrusive to say the least.
So as part of our second installment of spreadcheats we will learn how to tackle few of the most common data processing tasks:
Getting Unique Items from a List of Cells
There are 3 simple ways to do this:
- Using Advanced Data Filter
- Using countif() and auto filter
- Using formulas as described here
Assuming you have data as shown in the picture aside (and wishing you will have customers like those):
- First add a column to the left of the list. Here we will use formulas to fill numbers based on the uniqueness of the cell next to it.
- Essentially our formula should generate numbers in increasing order as long as the corresponding item is unique and not increase the number otherwise.
- So the formula for order column can be like this:
=IF(COUNTIF(list-upto-that-point, current element)=1,previous-order+1, previous-order)
See the example below:
remember, the first cell order is 1. - See how we are using both absolute and relative references to fetch the counts.
- Now add another column to the right of the list, here we will fetch unique items.
- We will use vlookup() to fetch each of the 12 unique items. The formula goes like this:
=VLOOKUP(running number,$B$4:$C$22,2,FALSE)
You can wrap the vlookup() with if() formula to avoid seeing #value errors.
That is all. Using this method you can extract unique items froma list.
Eliminating Doubles from a List
There are 2 ways in which you can find and remove duplicates(doubles) in excel lists with ease:
- Using countif() and then auto-filter
- Using formulas
The process for finding duplicates using formulas is same as that of finding unique items.
Instead of writing COUNTIF(list-upto-that-point, current element)=1, we now write COUNTIF(list-upto-that-point, current element)=2. Also the first element’s count should be changed to zero.
Once done the list should look like what you see on the side.
Finding Missing Items by comparing one list with another:
Even though this might seem like a different challenge, it is infact same as the above techniques. You need to use countif() to compare first list’s elements with second list. How? that is your home work.
Download and see these formulas in action:
Still having some doubts? Download the excel tutorial – unique & duplicate items and learn by poking around.
12 Responses to “29 Excel Formula Tips for all Occasions [and proof that PHD readers truly rock]”
Some great contributions here.
Gotta love the Friday 13th formula 😀
Great tips from you all! Thanks a lot for sharing! bsamson, particularly you helped me on a terribly annoying task. 🙂
(BTW, Chandoo, it's not exactly "Find if a range is normally distributed" what my suggestion does. It checks if two proportions are statistically different. I probably gave you a bad explanation on twitter, but it'd be probably better if you fix it here... 🙂 )
Great compilation Chandoo
For the "Clean your text before you lookup"
=VLOOKUP(CLEAN(TRIM(E20)),F5:G18,2,0)
I would like to share a method to convert a number-stored-as-text before you lookup:
=VLOOKUP(E20+0,F5:G18,2,0)
@Peder, yeah, I loved that formula
@Aires: Sorry, I misunderstood your formula. Corrected the heading now.
@John.. that is a cool tip.
Hey Chandoo,
That p-value formula is really great for a statistics person like me.
What a p-value essentially is, is the probability that the results obtained from a statistical test aren't valid. So for example, if my p value is .05, there's a 5% probability that my results are wrong.
You can play with this if you install the Data Analysis Toolpak (which will perform some statistical tests for you AND provide the P Value.)
Let's say for example I've got two weeks of data (separated into columns) with the number of hours worked per day. I want to find out if the total number of hours I worked in week two were really all the different than week one.
Week1 Week2
10 11
12 9
9 10
7 8
5 8
Go to Data > Data Analysis > T-Test Assuming Unequal Variances > OK
In the Variable 1 Box, select the range of data for week 1.
In the Variable 2 Box, select the range of data for week 2.
Check "Labels"
In the Alpha box, select a value (in percentage terms) for how tolerant you are of error.
.05 is the general standard; that is to say I am willing to accept a 95% level of confidence that my result is accuarate.
Select a range output.
Excel calculates a number of results: Average (mean) for each week's data, etc.
You'll notice however that there are two P Values; one-tail and two-tail. (one tail tests are for > or .05), the number of hours I worked in week two is statistically equivalent to the number of hours I worked in week one.
So here’s a way you might want to use this. You put up a new entry on your blog. You think it’s the best entry ever! So you pull your webstats for this week and compare it to last week. You gather data for each week on the length of time a visitor spends on your website. The question you’re trying to prove statistically is whether there’s an average increase in the amount of time spent on your website this week as compared to last week (as a result of your fancy new blog post). You can run the same statistical test I illustrated above to find out. Incidentally, it matters very little to the stat test whether the quantity of visitors differs or not.
Anyhow, the Data Analysis toolpack doesn't perform a lot of stat tests that folks like me would like to have access to. In those cases I have to either use different software, or write some very complicated mathematical formulas. Having this p-value formula makes my life a LOT easier!
Thanks!
Eric~
Fantastic stuf..One line explanation is cool.
Thanks to all the contributors
OS
Take FirstName, MI, LastName in access (you can fix it to work in excel) capitalize first letter of each and lowercase the rest and add ". " if MI exists then same for last name:
Full Name: Format(Left([FirstName],1),">") & Format(Right([FirstName]),Len([FirstName])-1),"") & ". ","") & Format(Left([LastName],1),">") & Format(Right([LastName],Len([LastName])-1),"<")
I teach excel, access, etc etc for a living and i have my access students build this formula one step at a time from the inside out to show how formulas can be made even if it looks complicated. Yes I know I could just do IsNull([MI]) and reverse the order in the Iif() function but the point here is to nest as many functions as possible one by one (also I illustrate how it will fail without the Not() as it is)
Extract the month from a date
The easiest formula for this is =MONTH(a1)
It will return a 1 for January, 2 for February etc.
if in a column we write the value of total person for eg. 10 if we spent 1.33 paise each person then how we get total amount in next column and the result will in round form plzzzzz solve my problem sir................... thank u
@Anjali
If the value 10 is in B2 and 1.33 paise is in C2 the formula in D2 could be =B2*C2
If the values are a column of values you can copy the formula down by copy/paste or drag the small black handle at the bottom right corner of cell D2
kindly share with me new forumulas.
How to convert a figure like 870.70 into 870 but 871.70 into 880 using excel formula ? Please help.