This week in Formula Forensics we’ll look at, Zebra Stripes and Checker-board Conditional Formatting.
This idea is inspired by a number of posts over the past few years asking about zebra stripes but specifically BobR who in in June 2011, also asked about Checkerboards in the post: Want to be an excel conditional-formatting Rock Star, Comment No. 154.
I got the conditional format for alternating row and column colors,
Is there a conditional format to make it a checkerboard whereas the cell A2 will remove either the conditional for the row or column and then alternately to A4, B1, B3 etc?
Chandoo responded fairly quickly with this Conditional Formatting formula:
=IF(MOD(ROW(),2)=1,MOD((ROW()-1)*8+COLUMN(),2)=0,MOD((ROW()-1)*8+COLUMN(),2)=1)
Unbeknownst to Chandoo I posted this about a minute later:
=ISODD(ROW()+COLUMN())
Both formula correctly answer BobR’s question.
So today we’re going to pull apart Zebra Stripes and Checker Boards and see what makes them tick.
As always you can follow along in a download file here: Download File.
ZEBRA STRIPES
Zebra Stripes as Conditional Formatting is simply applied using a simple formula within Conditional Formatting.
=MOD(ROW(),2)=0
Conditional Formatting requires a formula that returns a boolean “True” to apply a format or a Boolean “False” to not Apply a format.
So the formula is better read as: If MOD(ROW(),2)=0
And If MOD(ROW(),2)=0, the formula will evaluate as True
This is best evaluated as 3 columns on a worksheet.
In cells
B5:B10 The formula =Row() returns the Row Number
C5:C10 The formula =Mod(Row() ,2) returns the Mod of Row Number, divided by 2
The Mod function returns the remainder of the division of the Row Number divided by 2,
So in Row 5, Mod(Row(),2) = Mod(5, 2) = 5/2 = 2 Remainder 1 = 1
and in Row 6, Mod(Row(),2) = Mod(6, 2) = 6/2 = 3 Remainder 0 = 0
D5:D10 The formula =Mod(Row() ,2)=0 checks the remainder against the value 0
This is what evaluates to either True or False depending on the Row number.
Where the Values are True the Format will be applied (Even Rows)
The Conditional Formatting can be applied to Odd Rows If the Formula is slightly altered
=Mod(Row() ,2)=1
Similarly the formatting can be applied to Columns using
=MOD(COLUMN(),2)=0/1
CHECKER BOARDS
RobR received two responses to his Checker-Board Conditional Formatting request.
=IF(MOD(ROW(),2)=1,MOD((ROW()-1)*8+COLUMN(),2)=0,MOD((ROW()-1)*8+COLUMN(),2)=1)
and
=ISODD(ROW()+COLUMN())
Lest see what’s inside these two formula.
=IF(MOD(ROW(),2)=1,MOD((ROW()-1)*8+COLUMN(),2) =0, MOD( (ROW() -1)*8+COLUMN(),2)=1)
This is a simple If Formula with 3 components
=IF(MOD(ROW(),2)=1,MOD((ROW()-1)*8+COLUMN(),2)=0,MOD((ROW()-1)*8+COLUMN(),2)=1)
If Condition MOD(ROW(),2)=1
Value if True: MOD((ROW()-1)*8+COLUMN(),2)=0
Value if False: MOD((ROW()-1)*8+COLUMN(),2)=1
The If Condition is already known to us, as it’s the same formula used in the Zebra Stripes above.
It evaluates to True when it is on an Odd Row.
So when it is an Odd numbered Row Excel will look at MOD((ROW()-1)*8+COLUMN(),2)=0
And when it is an Even numbered Row Excel will look at MOD((ROW()-1)*8+COLUMN(),2)=1
We can notice that these are the same formulas which have a different ending of =0 and =1
MOD((ROW()-1)*8+COLUMN(),2)=0
This section Takes each Row subtracts 1 and then multiplies this number by 8. This can be expressed as simply as saying multiply the Row * 8.
This will always return an Even Number and could have been simplified to Row()*2
MOD((ROW()-1)*8+COLUMN(),2)=0
The next bit adds the column number to the previous Even Number.
So now this part will be Odd when the column is Odd and Even when the column is Even.
MOD((ROW()-1)*8+COLUMN(),2)=0
The remainder of the formula is the same as the Zebra Stripes formula.
An Odd Number (Odd Columns) in the section above will return a 1 as the result of =Mod(Odd,2)
An Even Number (Even Columns) in the section above will return a 0 as the result of =Mod(Odd,2)
When evaluated against 0 will return True for Even Columns and False for Odd Columns.
Now the exact same happens in the False section of the If formula except that it is evaluated against 1.
=ISODD(ROW()+COLUMN())
I tackled this problem from a different direction to Chandoo.
Knowing that Even + Even = Even and Even + Odd = Odd and that the row and Column Numbers increase in each direction by 1 each Row/Column, it was simply a matter of adding the Row and Column numbers together and checking if it was Odd or Even
The Excel function IsOdd() and IsEven() both return a Boolean “True” if the contents are Odd or “Even” respectively. This negates an external truth check as described above.
This is easily shown by adding a formula to the Checker area
=Row()+Column()
Excel 2003: The above formula won’t work in Excel 2003.
Try this instead =Mod(Row()+Column(),2)=1
If the alternate shading is required a switch to
=ISEVEN(ROW()+COLUMN())
Does the trick.
Excel 2003: The above formula won’t work in Excel 2003.
Try this instead =Mod(Row()+Column(),2)=0
Learn More About Conditional Formatting Here:
http://chandoo.org/wp/2009/03/13/excel-conditional-formatting-basics/
and
http://chandoo.org/wp/2008/03/13/want-to-be-an-excel-conditional-formatting-rock-star-read-this/
and
http://chandoo.org/wp/2008/10/14/more-than-3-conditional-formats-in-excel/
DOWNLOAD
You can download a copy of the above file and follow along, Download Here.
OTHER POSTS IN THIS SERIES
You can learn more about how to pull Excel Formulas apart in the following posts
Formula Forensics 001 – Tarun’s Problem
Formula Forensics 002 – Joyce’s Question
Formula Forensics 003 – Lukes Reward
Formula Forensics 004 – Freds Problem
We Need Your Help !
If you have a neat formula that you would like to share and explain, try putting pen to paper and draft up a Post as Luke did in Formula Forensics 003. or this post.
If you have a formula that you don’t understand and would like explained but don’t want to write a post also send it in to Chandoo or Hui.
13 Responses to “Gantt Box Chart Tutorial & Template – Download and Try today”
Hi Chandoo
As one of your students I have followed your detailed example through with great success. However, Excel is acting in an unexpected way and I wonder if you could take a look?
http://cid-95d070c79aef808e.office.live.com/self.aspx/.Public/Gantt%20Box%20Chart.xlsm
On my version, I have to type 40239 (Which equates to 2 Mar 2010) to get the chart to display 31 May 2010 (which should be 40329)!!??
Have I done something wrong or is Excel acting up?
Thx
Oli
PS Your example file in 2007 displays correctly.
Hi,
I like this idea a lot, but I agree the name is a little drab.
As an American I may just be seeing things, but to me the combination of lines and bars on your chart looks like a bunch of cricket bats.
Maybe you could work that into a catchier name. 🙂
Cheers!
Here is some code I use to keep the axis synched.
It may be useful to some of your readers
It is based on a comment I saw on Daily Dose of Excel.
Function SynchGanttAxis(Cname, lower, upper)
'Sets the X min and X max for Category axis
Application.Volatile
On Error Resume Next
'
'Top Horizontal Axis
With ActiveSheet.Shapes(Cname).Chart.Axes(xlCategory, 1)
.MinimumScale = lower
.MaximumScale = upper
End With
'Bottom Horizontal Axis
With ActiveSheet.Shapes(Cname).Chart.Axes(xlValue, 2)
.MinimumScale = lower
.MaximumScale = upper
End With
End Function
Function SynchVerticalAxis(Cname, lower, upper)
Application.Volatile
On Error Resume Next
' Excel 2007 only
'Right hand vertical axis
With ActiveSheet.Shapes(Cname).Chart.Axes(xlValue, 1)
.MinimumScale = 0
.MaximumScale = upper
End With
End Function
@Oli.. Can you check your file again.. I see 40329...
@Dave: Even I saw things.. the bars actually looked like lollipops. How about calling this lollipop chart - now that would be yummy and goes along the tradition of naming charts after eatables (bar, pie, donut...)
@Bob: Superb stuff... thanks for sharing 🙂
Hi Chandoo
This looks really good and I think it can also be applied to show project phases / milestones.
Question: Thinking further could this be amended to display a project lifecycle (Idea through to Implementation say 7 phases) on one bar / row? Just imagine 20 projects within a programme all on one chart one bar each showing their respective lifecycle stages i.e. on one page.
Idea: As the Gantt Box Chart this is quite intensive to set up re formatting etc how about the added extra of once you have completed this to "Save as template" i.e. saves the formatting and layout of the chart as a template so you can apply to future charts. Simple to do and will save the time formatting etc again and again and again.
Therefore tip: Click on your chart demo and then click on Save As template icon (2007) - edit file name and click on save. Ready to use / apply via Templates in Change Chart Type window.
Thanks and be very interested if the lifecycle question can be resolved
Mike
How embarrassing.
I was obviously suffering from numerical dyslexia. I was one of those days.
@Mike H: You can easily make this chart to work like a generic project lifecycle plan chart. All you have to do is,
1. in a separate sheet define the steps of lifecycle and various dates in a table (with 5 columns for each of the projects you have).
2. now use a control cell to input the project name you want to show in the chart
3. based on the input, use OFFSET Formulas to get the correct data
4. Rest is same as the tutorial above
For more info on the dynamic charting visit http://chandoo.org/wp/tag/dynamic-charts/ and http://chandoo.org/wp?s=OFFSET
Your solution is really smart but in the en Excel isn't meant to do stuff like this. I, as a former PM, always thought is was frustrating that you had to do stuff like this for something simple like a Gantt chart. So I built Tom's Planner. And would like to plug it here. I think it really solves the problem you are trying to solve in the most efficient way. Check out http://www.tomsplanner.com for a free account or play around with the demo.
Hi there,
Chandoo - this is really a very nice and helpfull chart - I adopted it, so I can report a forecast or the delay of a certain task (coming from my role as an auditor for projects).
One topic I´m currently struggeling with: I do have a project lasting for lets say 12 month. For a management reporting, I want to have kind of snapshot, lets say one month back and 2 month in the future. I tried with the offset formula, but failed. Any idea?
Thx
Lopi
[...] Ein viel geliebter Klassiker ist die Erstellung von GANTT-Diagrammen mit Excel. Wir hatten das Thema wiederholt schon hier. Chandoo.org hat sich mal wieder mit einer neuen Variante hervorgetan: Das GANTT-Box-Chart. [...]
[...] [...]
Hi Chandoo - fantastic xls. One thing I can't figure out how to do is adjust the alignment of the vertical axis. I would like to left align so that I could indent to represent sub tasks. Can that be done? Or is there a better way?
I've been trying to work out if there's a way to show weekends on the graph. The closest thing I've got is to add them on a secondary axis, but then I haven't been able to keep both axis lined up together! Any ideas?
Following on from this - is it possible to show things like holidays?