This article is part of our VBA Crash Course. Please read the rest of the articles in this series by clicking below links.
- What is VBA & Writing your First VBA Macro in Excel
- Understanding Variables, Conditions & Loops in VBA
- Using Cells, Ranges & Other Objects in your Macros
- Putting it all together – Your First VBA Application using Excel
- My Top 10 Tips for Mastering VBA & Excel Macros
In part 2 of our VBA Crash Course, we are going to learn what Variables, Conditions & Loops are and how to use them in Excel VBA.
What are Variables, Conditions & Loops?
If you are new to computer programming, you might think I am speaking legalese. So, to make it easy to understand, lets assume you run a bunch of stores across the town. To make it colorful, lets call your stores “We are nuts” – a dry fruit and nuts store chain. At the end of every day, you call each of the 24 store managers and ask them how much sales they have made in that day.
Now, you are not the kind of boss who micro-manages & nitpicks. So you don’t really note down sale for every store. Instead, as you call the store manager, you just mentally update the total. So first store says “$2,300” your total is 2300. Second manger says “$4,000”, the total now will be 6300. So on.
The value 6300 here is nothing but a variable.
A Variable is a small chunk of computer’s memory used to store a value.
Although you don’t micro-manage, you are certainly concerned, whenever a “we are nuts” store reports sales that are too low or too high. You then speak with the store manager for few extra minutes to understand what is going and how you can help. Lets just say, this threshold is $500 for low sales and $5000 for high sales. So anytime a manager reports values beyond this limit (500,5000), you spend some time discussing the business and learning what is going on.
This sort of thing is nothing but a condition.
A Condition is a logical check computer performs to test something. For eg. Sales < 500 or Sales > 5000 is a condition.
And now the whole process of each of the 24 store managers calling you and reporting the daily sales is nothing but a loop. They call you everyday and do the same thing.
A Loop is a set of instructions meant to be followed certain number of times.
![Understanding Variables, Conditions & Loops in Excel VBA [Part 2 of 5]](https://chandoo.org/img/vba/crash-course/using-variables-loops-conditions-in-excel-vba-how-to.png)
Using Variables in VBA
Variables as we learned, are small chunks of computer memory used to store and retrieve a value. We can use them to store numbers, text, ranges of cells, charts or pretty much anything when it comes to VBA.
As with anything else, Variables too have a life span. Some variables die as soon as the SUB in which they are created ends. Some variables (declared at module level) have better life span as they go to gym and eat healthy food.
How to create variables in VBA?
Whenever you want to use a variable, you must create them first. This is your way of telling computer to set aside some memory units so that your variable can be used.
In Excel VBA, you can do this by the DIM statement.
For eg. below are some variables declared in VBA.
Dim someNumber As Integer
Dim otherNumber As Double
Dim someText As String
Dim aCondition As Boolean
Dim myCells As Range
Dim myChart As Chart
Dim myList(1 To 10) As String
Dim anotherList() As Variant
By default, you can use variables without defining them in VBA. That means, if we write someNumber=12 without writing any DIM statement corresponding to it, your VBA code would still work. But this is not a good practice. Mainly because, if you are not declaring variables, then you don’t know what is available for you to use.
You can force Excel to throw up an error whenever you did not declare variables by adding the statement option explicit at the top of your code.
As you can see, this is almost like plain English. Let us understand 2 of these lines. The rest you can figure out easily.
Dim someNumber as Integer: This line tells Excel that you want to have a variable with the name someNumber which is of the type Integer. This means, you are going to use someNumber variable to store integer values only. Please note that Excel VBA integers are capable of storing values from -32,768 to 32,767 only. If you want to store bigger (or smaller) numbers, you can use the types Long or Double.
Dim myList(1 to 10) as String: This line tells Excel that you want to use a list of values (called as arrays in computer lingo) of String (text) type. The list size is defined to be 10. You can access individual items of the list by using the item number, like this: myList(2) points to second item in the list.
How to use variables in VBA?
Once you have created a few variables, you can use them in your VBA code. A few examples below.
| VBA Code | What it does? |
| someNumber = 2 | Stores 2 in to the variable someNumber |
| someText = “Hello” | someText has the text value hello |
| someNumber = someNumber + 1 | Increments the value of someNumber by 1 |
| myList(2) = 812 | Sets the value of 2nd item in myList array to 812 |
| activeCell.Value = someNumber | Places the value of someNumber in currently selected cell |
| someNumber = activeCell.Value | Places the value of currently selected cell in someNumber variable |
Using Conditions in VBA
Almost everything we do involves making decisions & testing conditions. In the “we are nuts” example, we are testing the condition of sales less than 500 or more than 5000 and then doing something based on that.
You can use various statements in VBA to test for conditions. We will learn the simplest of them. IF and THEN statement.
Using IF THEN Statement in VBA
VBA’s IF Then statement looks almost like plain English. Here is an example to test the Sales condition.
If ourSales < 500 or ourSales > 5000 then'special instructions to handle too many or too little sales
end if
The above code should be obvious to you by now.
Using ELSE statement in VBA
Just like IF THEN statements are used to test a condition and do something, ELSE is used to do something when the IF condition is failed.
For eg,
If ourSales < 500 or ourSales > 5000 then'special instructions to handle too many or too little sales
Else
'Note down the sales & move on
end if
Would just note down the sales figures if the sales are between 500 and 5000.
Using Loops in VBA
A Loop is a set of instructions meant to be followed specific number of times, as defined earlier. In “we are nuts” example, we are calling and asking for sales 24 times. That means we are doing the same set of operations (call, ask for sales, if the sales are too low or too high do something, hang-up) 24 times, in a loop.
In VBA, there are several different ways to write loops. We will see the easiest type of loop today. For more, please consider joining our Online VBA classes.
Using FOR Loop in VBA
A for loop repeats a set of VBA instructions any given number of times. For eg.
For storeNumber = 1 to 24'call the store
'ask for sales figures
'do something if needed
'hang up
Next storeNumber
Would run for 24 times and each time repeats the same 4 steps (call, ask, do, hang-up).
Using FOR EACH Loop in VBA
FOR EACH is a special type of loop in Excel used to run same instructions for each of the various items in a list.
For example,
For Each cell in Range("A1:A10")cell.value = cell.value + 1
Next cell
would run 10 times and increment each of the cell’s values by 1 in the range A1:A10.
Putting it all together – a Simple VBA Program to Note Down Sales of 24 stores
Now that you have learned 3 key ingredients of VBA – Variables, Conditions & Loops, its time we put them together to do a small VBA program.
A Demo of our Daily Sales Log VBA Application
Before we jump in to the code, lets just take a look at how it would work. I have shown it only for 5 stores. But it works for 24.
The Code behind our Daily Sales Log VBA Application
Here is the code that captures the sales of 24 stores whenever you click on the “Capture Sales” button.
Sub captureSales()
'when you run this macro, it will take the sales of all the 24 stores we own
'it will ask for a reason if the sales are too low or too high
Dim storeNum As Integer
Dim reason As String
Dim store As Range
storeNum = 1
For Each store In Range("C7:C30")
store.Value = InputBox("Sales for Store " & storeNum)
If store.Value < 500 Or store.Value > 5000 Then
reason = InputBox("Why are the sales deviated?", "Reason for Deviation", "Reason for Deviation")
store.Offset(, 1).Value = reason
End If
storeNum = storeNum + 1
Next store
End Sub
How this code works?
By now, you are already familiar with various parts of this code. So I will just explain the alien portions.
- Dim statements: These lines declare the variables we are going to use. Notice the different data types (Integer, Range etc.) we have used for various types of data we want to hold.
- For Each store In Range(“C7:C30”): This line is going to tell excel that for each store (ie cell) in the range C7:C30, we need to repeat the instructions all the way until Next Store. In our case, Excel is going to repeat for 24 times.
- store.Value = InputBox(“Sales for Store ” & storeNum): This line shows a small box to you and asks for your input. You can enter a number and press OK (or enter). Whatever value you enter will be placed in current store’s cell.
- reason = InputBox(“Why are the sales deviated?”, “Reason for Deviation”, “Reason for Deviation”): This line shows a box to user with a title and default value (Reason for deviation).
- store.Offset(,1).value = reason: This statement places the reason for sales deviation in to the cell right to the store sales. Offset(,1) does the trick here.
Download Example Workbook & Learn about Variables, Conditions & Loops in VBA
Click here to download the example workbook and learn more about variables, conditions & loops in VBA.
What Next – Understanding Cells, Ranges & Other Objects in VBA
In the part 3 of this tutorial, learn how to use cells, ranges & other objects from VBA. Stay Tuned.
If you have not read, please read the first part of this series – Introduction to Excel VBA – What is it & How to write your first VBA Macro.
How do you like this Example?
How do you like the VBA examples shown in this article? How would you enhance the macro to do more? One idea is to add another button to clear previous day’s sales.
Please share your views & ideas using comments. I like to learn from what you share.
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37 Responses to “Pie of a Pie of a Pie chart [Good or Bad?]”
If I could have the same quality of graphics and illustration in Office Apps, I would certainly use it.
If I could have the same quality of graphics in Office Apps (Excel, PPT) I would certainly use it.
Chandoo,
First, let me say I love your blog. I like this post, and I think that technically (in terms of readability of data) your argument is correct. The bar of bars, and the table, are much better for readability and accuracy, and as you say would be much easier to produce.
But these points ignore the context of the chart. If the chart was part of a scientific paper, your solution would be a valid one. The context in this case is an illustrated atlas of wildlife. A companion graphic to go with written text. The importance of aesthetic goes up over readability and accuracy. Much of the data and points (I assume) will be covered in the text.
There's always a pure technical tufte-esque argument. But I sometimes think it ignores the value of aesthetics. (Which I admit are quite subjective)
Great post though. Thanks.
The Treemap makes the scope of the data much clearer! The 3D pie chart depiction is deceptive.
This reminds me of the videos ive seen on the internet where it compares the relative sizes of the earth with the larger planets, then the sun, then other stars in the galaxy. Eventually there is an image showing the largest star in the sky with a little pixel representing the sun.
My point is if you varied the size of the charts it would help convey the message. The first chart (salt vs fresh) would be the biggest and the rest would be arranged in descending order. I feel this would be more accurate.
It may be helpful to consider the advice of Steven Few and Edward Tufte regarding pie charts in general. To summarize, they are seldom the most useful way to present data. Here's Few's thoughtful piece on the subject.
http://www.perceptualedge.com/articles/08-21-07.pdf
Try putting the percentages on the bar charts instead of actual amounts. Lakewater would be .013 % instead of 52.
That is very good pie chart example.
Please send example file if it is possible.
It will work , even though colors may be confusing , it can be labeled well . Also it can be called as the drilled chart , as it drills in information further , like the first chart may show business in a region , second may drill into a particular region , thrid may further drill into wat products are there in that region . It works well for me , i would more vote for the 2 nd option .
Overall all this site is awesome ,
p.s : just like me
The risk with pie of a pie of a pie chart is that Jon may have a seizure by looking at it. Also, it isn't easy to read. 😉
I dunno. The only thing worse than a pie chart is a cascading series of pie charts. I don't even think they really lend themselves to this sort of thing. It just becomes a big hide-the-ball game with your viewer.
Those goofy connectors between the pies are pure chart junk. I can't really tell if the second chart has 2 series or 3 - because the connector is a different color than the 2 labeled slices. Despite that, even whereas the drill down kind of works, still the individual components suffer from the same old weaknesses that 3d pie charts have.
Use a large bar chart as your "cover story", and fill in the sub points with smaller bar charts - or even go grab the Fabrice SFE project for extra butter. Use page orientation, color, and some text styles to guide your audience through the drill downs.
FWIW, if you check out the guy's site, you can find several other truly mortifying charts:
http://www.andrewdavies.com.au/index.html
The methane emissions one is particularly heinous. Although, I'm kind of debating what I think about the 'Glacier Changes" chart. I'd kind of like to see the data on that to see how it would look in a more traditional horizon chart.
Thank you, that was scary. I don't understand the "Glacier changes" Chart at all...
Its a very nice way to represent the data, especially when we have sets and sub-sets within the data.
I like these!
Except for the fact that they aren't dynamic and hence must be setup manually each time
It would also be nice if they could be interrogated as in select a different segment and the new data falls out automagically, but then none of the standard Excel charts do that either.
I'd like it better if the bars were stacked. How about this idea (I hope I can convey it in words):
First bar is vertical and stacked.
Second bar is horizontal, stacked horizontally and the same proportion had it been on the first bar.
Third bar is vertical, stacked vertically and the same proportion had it been on the second bar.
Then it would really look like you are zooming on the chart, like the Powers of Ten video, or maybe like the golden ration spiral.
These looks shunting but setting up for each step makes kicks them out. However if these can be arranged automatically by native excel or by VBA, these will be the part of my "Archery"
I agree with Chandoo's Suggestion about the Bar Graph which represents data in a very appropriate manner. Even I prefer doing the same. I seldom use Pie Chart unless required.
That's a real nice example of a missleading infographic. But to be honest, I think chandoos suggestion is not much better!
Why are pie charts bad? I think because they don't show the real size-relations. The biggest pie in that example ist 300k big. The 2nd one has only the size of 10k, about 3% of the first one. Niether the pies nor the bars show the real sizes. I jnow, it's hard to show the sizes because the values of the second and the third pie are so small. But that's what visualization are about - showing relations to allow the reader to see the real sizes!
So how to show the real figures?
First possibility is o use a 1:1 scaling. Well then, you need a very big screen to show also after a 90° rotation, wihich I would prefer because it's a structural comparison and not a timeline. Maybe that solution is not the perfect way.
The other chance you have is to zoom in but to really show that you zoom in! http://www.pro-chart.de/images/Water_Fall.png maybe gives you a first impression what i mean. (i was a quick try, done in 10 minutes)
The next way is, maybe to fold the bars like in the financial report 2011 of the Post of Switzerland page 22. That chart is based on an excel chart. Maybe can explain you how to do it 😉
Financial Statement: http://www.post.ch/en/post-startseite/post-berichterstattung/post-berichterstattung-service/post-berichterstattung-downloads/post-gb-2011-finanzbericht.pdf
page 22: http://www.pro-chart.de/images/FS_Schweizer_Post.png
A way that is not so very common is to divide the bars in a lot of single datapoints. So maybe the 390k bar then consists of about 5,000 single datapoint. That's not possible - it is! Have a look:
http://www.pro-chart.de/images/Dotted_WF.png
It's pure excel!
Now one single point ist 0,2% of the whole (in the example above). Add more datapoints and you can visulize the very big and the very small numbers!
Wish you a lot of fun - visualizing with excel can be very powerful!
Joerg
...if you would like to know how these charts work, just send an email to J.Decker@pro-chart.de
Hey Joerg,
I don't dig so much the dotted waterfall thing. But this is kind of awesome:
http://www.pro-chart.de/images/FS_Schweizer_Post.png
Can you help me on the bar of bar graph? Would it be possible to create that from pivot table? Can you show me how to create the bar of bar graph?
do nothing but say "Awesome!"
You are a Rock star.....This seemed an answer as if someone was reading my mind and just had the solution to my questions on what I exactly was looking for .....What a Fab !!
can u explian me step by step
Can anyone please explain how to make this chart please.
Do you mean the pie of a pie chart or the folded bar chart?
Joery PIE OF PIE Chart please
Can someone please explain how to make PIE OF PIE Chart.
@Mandeep
The last line of the post is:
PS: If you want to know to create this pie of pie of pie chart in excel, see here.
Due to forum migration, link is now:
http://chandoo.org/forum/threads/multiple-pie-chart.7343/
Hi... i love these charts.... can any one show me how to draw these charts in excel 2010
@Vamshi
The very last line of the post refers you to:
PS: If you want to know to create this pie of pie of pie chart in excel, see here. http://chandoo.org/forums/topic/multiple-pie-cahrt
Where is the attachment....it used to be there...i have seen this before but now i am not able to find...
See this:
http://img.chandoo.org/playground/WaterDistribution-chandoo.xlsx
And this:
http://chandoo.org/forum/threads/how-do-you-create-this-chart.9743/
Normally I don't learn post on blogs, however I would like to
say that this write-up very compelled me to try and do so!
Your writing style has been amazed me. Thank you,
quite great article.
This is very impressive, I would like to learn how to build this for myself. I have tried for some time now, is there a step by step process on how to create these waterfall pie of pie charts?
I am novice to excel and use it very seldom. But your blog contains to the point information one needs to get going.
I was searching for a trick to do a Pie chart drill down - for example the first pie chart shows how the prices are distributed between perishable and non-perishable items.
Now if we want to know how the perishable items are distributed - one can click the segment and it will draw another pie chart with distribution of all different perishable items (milk,meat,fruit,veg etc)
So do you have any such trick?
Regards,
electrojit
I like the look of your pie of pie of pie chart, although I understand that the relative size of each pie does not represent the actual percentages.