In our Utopian imaginations all the data would have been standardized and shareable across systems and people. But alas, the reality is totally different. We seldom get data in the format / way we desire it to be. In other words, the ingredients are all there, but for us to prepare the dinner, you must pre-process them.
Often this pre-processing or cleaning up the data takes quite an amount of time it self leaving very little to do the actual work. That is when you can use excel’s powerful data cleaning techniques to handle the situations.
One common problem with corporate data is incorrectly formatted phone numbers. Most of us are used to a standard 10 digit phone number format like 123-123-1234 or (123) 123 1234, but when you get that customer data, very few phone numbers in it are formatted like above. Instead you might see phone numbers like 1231231234, 12312 31234, (123)123-1234 etc.
It is not really difficult to clean up the phone numbers if we know before hand how they are formatted. For eg. you can easily convert a phone number like 1231231234 to 123-123-1234 using excel text formatting functions like =TEXT(1231231234,"000-000-0000"). But it is a rare case in which we have control over the incoming format and quickly you will have to use a slew of format / text processing functions to clean up the data.
To simplify the whole thing, I have written a small VBA UDF (User Defined Function) which you can add to your excel add-ins list and use to clean up virtually any phone number format to standard phone number.
Function cleanPhoneNumber(thisNumber As String) As String
' this function aspires to clean any phone number format
' to standard format (+9999) 999-999-9999 or 999-999-9999
' works with almost all phone number formats stored in text
Dim retNumber As String
For i = 1 To Len(thisNumber)
If Asc(Mid(thisNumber, i, 1)) >= Asc("0") And Asc(Mid(thisNumber, i, 1)) <= Asc("9") Then
retNumber = retNumber + Mid(thisNumber, i, 1)
End If
Next
If Len(retNumber) > 10 Then
' format for country code as well
cleanPhoneNumber = Format(retNumber, "(+#) 000-000-0000")
Else
cleanPhoneNumber = Format(retNumber, "000-000-0000")
End If
End Function
The above function is pretty straight forward and simple. It scans the input text for any numeric ASCII codes and saves them to another text field. Once the scanning is complete the function will format the final number to 999-999-9999 format if the number has 10 or less digits, otherwise to (+9999) 999-999-9999 format (with country code).
Like this? Learn these other data cleaning / processing tips:
Handling spelling mistakes in your data
Splitting text using excel formulas
Generating initials from names using excel
Adding a range of cells using Concat()
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.