A while back I developed a solution to a Chandoo.org Forum question, where the user wanted a 4 level doughnut chart where each doughnut was made up of 12 segments and each segment was to be colored based on a value within a range.
You can read the original post here: http://forum.chandoo.org/threads/hourly-goals-chart.30621/
This post will examine the techniques I used for the solution.
Download the sample file: Download Hourly Goals Chart File
The first thing to note is that there are 4 column of data, one for each measure of Safety, Quality, Delivery and Cost.
Secondly is that each measurement has 12 values representing the times from 4:30 am to 3:30 pm.
We need to setup a Doughnut Chart with 4 layers of 12 segments each
The easiest way to do this is to replicate the data area, but fill it with the same value in all cells,
I choose 1, but as long as all values are the same value, it can be any value
Add a Doughnut Chart
Select the Range A16:E28
Goto the Insert, Chart and select the Pie/Doughnut menu
We have a bit of work to do yet to get the charts format correct
First select the chart then select the Chart’s Legend and press Delete
Next with the chart still selected, Right Click on any Doughnut and select Format Data Series
Set the Doughnut Hole Size to 25%
Do not change the angle of the first slice
Right click on the Outer Doughnut and select Add Data Labels, Data Labels
Right Click on any Data Label and Select Format Data Labels
Tick Value From Cells, Select a range A17:A28
Untick Leader Lines
Now manually click and drag each data label outwards to its final location
Finally set the Border Color for the doughnuts
Right Click on each Doughnut in turn
Set the Doughnut’s Border Line to a Grey Color and a 2 Pt line size
We can now add a text box for the Doughnut Labels
With the chart selected, goto the Insert, Text Box menu
Drag a Text Box inside the chart
Right click on the Text Box and edit Text and type in the value Cost
Now repeat this for the other 3 Doughnuts
Connect the Doughnut Segments to the Data Area
We now have a basic Doughnut chart with all the facilities we require.
Unfortunately, Excel doesn’t have a built-in Conditional Formatting option for charts.
So we will need to develop a system using some simple VBA.
Understand the Doughnut Chart
To write a piece of code we will need to loop through each segment of each doughnut and reference it back to the source data area
Then use some code to set the fill color
then repeat for each segment
To do this we need to understand which doughnut is which column of data and which segment in the doughnut is which time period
First select the inner Doughnut, Note that when you select it, Excel highlights the Safety Series as well as showing the Series Number in the Formula Bar
Repeat with the outer Series and you will see that Doughnut 4 is connected to the Cost Data and is series 4.
To determine which segment is which goto cell E17 and change the value from 1 to 2
So we understand that the series go from Value 1 to 4, Inner to Outer Doughnuts and that the segments go from value 1 to 12 clockwise, starting to the right of 12 O’Clock.
Finally select the Chart and make note of it’s name.
The Charts Name is shown in the Name Dialog above cell A1
Now for some VBA
Lets start by first manually recording a macro in VBA and we will then edit and add to the macro to get our final result
Start the macro Recorder by Pressing the Macro Button in the lower left corner of the Excel Window
Note the Macro Name, which is most likely Macro1 and press Ok
Now everything that you do is being recorded by the Visual Basic Editor (VBE)
Select the Outer Doughnut, then select Segment one, then Right Click on Segment one, Format Data Point
Select the Fill & Line menu
Set the Fill to a Solid Fill and Select a Color Red
You can now stop macro recording by pressing the Macro button again
Lets look at our code
To change to VBA press the Alt+F11 button
You should have a screen similar to this:
Take note of the above.
We can see that we have a Macro1 subroutine, located in Module 1 of our Excel file.
If you can’t see a Properties or Immediate window, don’t worry.
Looking at the VBA Code we can see
- That the chart is called Chart 1
- We selected Doughnut 4, the outer doughnut
- We selected the first segment in Doughnut 4
- We set the Fill Color of Segment 1 to Red = RGB(255, 0, 0)
So this little bit of code will form the basis of our macro
What we need to do next is to place that within 2 loops, one loop for the Doughnut and one loop for the Segment
So lets do that:
You can see above that we have initialised two variables Doughnut and Segment as Integers
We have setup two loops, one for the Doughnut which will loop from 1 to 4 and a second loop for the Segment, which will loop from 1 to 12.
We can now use these variables within the code to reference each Doughnut / Segment as relevent
The next thing is to add lines to lookup the value of the measure in the original data table.
We can use our variables to assist us with this:
I have added a new variable declaration myVal and declared it an Integer as it is only storing the values from, 0 to 3.
Then we retrieve the value from the data area by using a Range(“”).Offset(Row,Column) combination.
We know that the segment loops from 1 to 12 and this is the Row Offset in each Doughnut.
The Doughnut loops from 1 to 4 and this is the Column Offset from the cell A1
Next we need to allow for each fill color remembering that the data area has a legend
We could loop from a value of 0 to 3 and check the new variable myVal against each value and set the color.
But VBA has a Select Case function which is ideally suited to this task
A also took the opportunity to streamline the Chart selection process in the previous step
That allowed the use of the With Object construct, allowing the Select case to use the myVal to apply different colors to the fill property of each segment
At this stage we can run the code, by simply pressing F5 in VBA
We can change the code to allow it to update automatically when Data range changes
To do this we need to shift the code to a Sheet1 Code Module associated with Worksheet Sheet 1
Note above that the code is now located in a Private Sub Worksheet_Change event. This means that the code runs whenever worksheet1 chnages.
The next line If Intersect(ActiveCell, Range(“B2:E13”)) Is Nothing Or Target.Count > 1 Then Exit Sub
Checks whether the cell that changed was not part of our Data Area or that multiple cells were selected.
If either are are true the macro ends
Then finally I removed the MyVal calculation and made it part of the Select Case function.
because we aren’t using myVal I removed the Dim myVal statement
We can now also remove Module 1, right click on it and Remove Module.
Save the file and return to Excel with Alt+F11
You can now change any cells in the data area and the macro updates the chart accordingly
Can we tidy up the layout of the worksheet?
Although we now have a fully functional model, we are stuck with an ugly worksheet layout because our template of 1’s is being used to support the framework of the 4 Doughnuts in the chart.
What if there was another way to achieve that?
Well there is.
Firstly, we could simply shift the range A18:ER30 well away from the Chart and data area or even move it to another worksheet.
This will work, but risks a person adding data, rows or columns and messing up the layout
But there is a better way
I am going to add 4 Named Formula to the worksheet, one for each Doughnut
Goto the Formula, Name Manager Tab and add 4 Names as listed below:
The 4 Names now contain an array of 12 x 1 each with a value 1.
We can use that to link the Doughnuts to instead of the Physical Range
Right click on the chart and Select Data
Select each Doughnut in term and Edit
Change the Series Name to Row 1 and insert the Names into the Series values dialog.
Note that the formula must include the Worksheet name =Sheet1!_Safety etc
Repeat this for the 4 Series
You can now select the framework range: A18:E30 and press Delete
The chart remains intact and is now supported by the Named Formula
Change some values in the Data range at the top and the Chart updates as it should.
You can download the final version of the file here: Download Completed File
The technique applied to the doughnut chart above can fairly easily be modified to any chart type or in fact any other shapes.
Let me know what you think in the comments below:
ps: This has been one of my hardest posts to write, simply because Microsoft has misspelt Doughnut. In my native Australian English it is Donut.