Recently I saw an interesting Earth Venus cosmic dance video on Facebook. See the original video below or here.
Although this is not entirely accurate from physics & astronomy perspectives, the dance is a stunning example of patterns that are generated by simple things.
I wanted to recreate this cosmic dance in Excel. How else am I to get my spreadsheet fix on a Saturday?
Here is a quick demo of the final outcome. Read on to learn more about the Earth Venus cosmic dance.
The details & assumptions
To create this cosmic dance, we need a few details
- Distance from Sun to Venus & Earth – 67.2 and 93 million KM respectively
- Number of days it takes to rotate around the sun – 224.7 and 365.25 respectively
We will also assume these incorrect things to keep our model simple
- Orbits of Earth & Venus are circular with Sun at center: In reality, they are elliptical, but as these are just stretched circles, we can assume circular orbits to keep the math simple.
- Sun is static: In reality, Sun (and entire solar system) is also moving. This means, this cosmic dance may never occur.
We also need one critical detail to graph this cosmic dance:
- The angular interval for plotting the lines. In the above examples, I have used 10° (ie there will be 36 lines around the circle). This is denoted by named range m in the model. You can adjust this in the output worksheet using a form control. Different values of m yield different patterns (although most of them will be pentagonal).
The math:
Generating planetary co-ordinates:
In a table, we will generate the positions (X & Y co-ordinates) of both Venus & Earth for 3000 points in time, each incremented by m degrees, starting at 0°.
To generate the X & Y values, we will use the x=r.cos? and y=r.sin? equations (where r is the distance from Sun and ? is the angle).
Drawing the lines:
This is the tricky part. At each step in the animation our line should from one tooth of the saw tooth pattern. See this demo to understand.
For more about this technique read – interactive network chart to map relationships between people.
So during each step of the animation, we add more co-ordinates to the chart (scatter plot) to generate this saw tooth pattern. Over time, this will yield the beautiful pentagonal cosmic dance.
We can generate these successive Venus & Earth co-ordinates from the calculations performed earlier by using MOD & INDEX formulas.
Once such saw tooth line data is generated, we will designate a cell to hold current animation position. Let’s call this pos.
We will then create two named formulas – dance.x and dance.y. These will contain the data necessary for our scatter plot. We will use OFFSET formula to generate these dynamic named formulas.
The chart
Now that all the necessary calculations are done, create a scatter plot with the dance co-ordinates. Set up X & Y axis minimum and maximum values accordingly (-160 to 160 should do). This ensures that the chart remains same no matter what step of animation we are on.
Also, add 3 more series to the chart
- One for a dot to represent Venus at current position
- One for a dot to represent Earth at current position
- One for a line connecting Venus to Earth
The animation
Next, let’s add a small macro to animate the chart. This macro will increment pos from 1 to a large number. After each iteration, we will call DoEvents so Excel can re-draw the chart. That is all.
Download the Earth Venus dance workbook
Click here to download the Earth Venus cosmic dance workbook. Enable macros to enjoy the dance. Play with form control to adjust the animation speed and pattern. Examine the data tab to learn more about the calculations.
Did you enjoy the dance?
I really liked the original video on FB and that is why I recreated this in Excel. This is a great exercise to show the power of simple things generating extraordinary patterns.
What about you? Do you like this Earth Venus dance?
More Excel animation and fun:
If you like animating things, you are going to love these tutorials. Check out,
15 Responses to “Highlight Employees by Performance Rating – Conditional Formatting Challenge”
While this might solve the question Shelly asked, there is another option that might be more useful - a pivot table could make a list of people who fall into the various categories, so, if you needed to simply see who got in the top bracket to give them a bonus, you would have that list
Simply sorting by the rankings would work too, but you would knock them out of alphabetical order.
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The solution I chose makes use of the percentile formula.
The percentile formula returns the value representing the K-th percentile of a range of values. The range of values is the first criteria, and K is the second criteria in the formula.
I applied Conditional Formatting according to the formulas in the order below:
5% =$C6>=PERCENTILE($C$6:$C$33,0.95) Dark Blue
15% =$C6>=PERCENTILE($C$6:$C$33,0.85) Light Blue
65% =$C6>=PERCENTILE($C$6:$C$33,0.1) Green
10% =$C6>=PERCENTILE($C$6:$C$33,0.05) Light Red
5% =$C6<PERCENTILE($C$6:$C$33,0.05) Dark Red
The issue I noted with this approach is that Zambi was not highlighted in my solution as it is in the solution provided. Unless I am mistaken, and I very well may be, the 10th percentile for this data set is at 2.21, so Zambi would fall above the 10th percentile with a PR of 2.3.
The first step to this was figuring out the 'buckets'; what scores should fall into each range. In attempting to match the formatting of the spreadsheet, I determined the buckets below.
5% = 95% to 100%
10% = 90% up to but not including 95%
65% = 10% up to but not including 90%
10% = 5% up to but not including 10%
5% = under 5%
After that, it is a relatively simple matter to plug the necessary values into the conditional formatting formulas as shown above.
One final consideration is that while the buckets above match the color banding on the spreadsheet, I believe that the original request suggests a different color banding with 6 buckets shown below.
Top 5% = 95 to 100% Dark blue
Top 10% = 85 up to but not including 95% Light blue
Top 65% = 35 up to but not including 85% Green
Bottom 10% = 10% down to but not including 5% Light Red
Bottom 5% = 5% or under Dark Red
This leaves one final bucket of 10 to 35% (exclusive of both values) that is not highlighted and so would remain white.
Thank you Chandoo and Shelly for an interesting and useful exercise. This is certainly a valuable technique to have in my reporting bag of tricks.
Use of PERCENTILE is a smarter way of doing it. Below is my solution.
First 5 % = Apply conditional formatting (Dark Blue) as highlight ">=" =PERCENTILE(C:C,0.95)
Next 15% = Apply conditional formatting (Lighter Blue) as highlight between =PERCENTILE(C:C,0.95)-0.01 and =PERCENTILE(C:C,0.8)
Next 65% = Apply conditional formatting as highlight (Olive Green) between =PERCENTILE(C:C,0.8)-0.01 and =PERCENTILE(C:C,0.15)
Next 10% = Apply conditional formatting as highlight (Lighter Red) between =PERCENTILE(C:C,0.15)-0.01 and =PERCENTILE(C:C,0.05)
Bottom 5% = Apply conditional formatting (Red) as less than =PERCENTILE(C:C,0.05)
I agree, this is a challenge faced by HR managers every year and use of percentile formulae is the most popular solution which permits further processing like making bell curve, applying increments based on segmentation etc.
Hi Chandoo,
I came at the same solution as yours (not looking at yours first) but I have hard coded the conditions in the conditional formatting. For example:
=AND($C6>=$D$10,$C6<$D$9)
I have done the same thing 5 times for each condition. This makes the formatting independent of the order of specification. I think it will work better across versions of excel.
To copy the same thing in all sheets, Shelly can copy these formatted cells with format painter and apply it to the relevant cells in next sheet and so on! I know 700 sheets will be difficult but I dont know of any other way to apply conditional formating rules to the whole sheet.
First i have used percentile formula in the next column of "percentile Threshold" where E5, E6.. is input to colour code.
The idea behind doing this is to replicate the formula for any range and any threshold
=PERCENTILE($C$3:$C$30,1-E5)
=PERCENTILE($C$3:$C$30,1-E6)
=PERCENTILE($C$3:$C$30,1-E7)
=PERCENTILE($C$3:$C$30,1-E8)
=PERCENTILE($C$3:$C$30,1-E9)
Now i have given logic to different employee by applying "if Formula"
=+IF(J3>=$G$5,1,IF(J3>=$G$6,2,IF(J3>=$G$7,3,IF(J3>=$G$8,4,5))))
where 'J" referes to PR and "G" refers to percentile derived from above mentioned formula.
once again it is replicable (just change reference points)
Now comes the major part of Conditional Formatting, i have used "use a formula to determine which cells to be formatted"
Formula =$j=5, format "required colour" Applies to "$I$3:$J$30"
plus put tick on stop if true
This solves the query, important point that this is repeatable and can be done for n number of departments
Thanks !
I had done some reading on it and in Excel 2010 a new function has been introduced, percentile.exc. Attaching a video which also talks why the old percentile function shouldn't be used as it acts erroneous at times. Might be worth a watch Chandoo,
http://www.itechtalk.com/thread10579.html
@Deepa
Quit correct.
Where ever you use statistical spreadsheet functions and are using excel 2010 you should use the new versions of the functions as MS did a lot of work to speed up and fix errors in the old functions.
Warning: If you use the new Excel 2010 statistical functions in Named Formulas most of them will crash excel so do keep that in mind.
Hello Chandoo,
When i first read the challenge file, i thought, the color that need to be applied for a given rule, also need to be picked dynamically as given in rule set. But in the solution file, i found that color is hard Coded. So in case, someone has same data, but wants different colors, he/she needs to goto manage rules and change colors.
Let me know if my understanding is correct, and if yes, can we also make the color to be applied dynamic?
Thanks
Kishore
HI I ALSO USED THE PERCENTILE FUNCTION. HOWEVER, I WENT A STEP FURTHER AND USING THE SMALL() FUNCTION I SORTED THE DATA BY PERCENTILE SO THE COLOSCHEME WOULD BE GROUPED BASED ON THE VALUE. THIS WAY IT IS BETTER AND EASIER TO VIEW.
[...] recently posted a challenge to help a reader with a [...]
Hi, i have got doubt regarding to the percentages that has been put in chandoo's spreadsheet, i cant understadn how he put directly. can some one please explain how chandoo put the percetages straight way that i stated below..
5%
15%
60%
10%
5%
I have stumbled on this post as the solution has been already given so I have taken the liberty to record a video where I show the implementation of it as well as adding a filtering feature which I hope can prove to be useful.
Thank you
http://www.xlninja.com/2012/06/28/how-to-use-excel-to-highlight-employee-performance-rating/
[...] scriu nici macar un cuvant din urmatorul articol. Astazi mi-am citit mailul si hopa challenge de la Chandoo. Cum puteam sa refuz asa ceva si m-am apucat de citit, iar dupa 5 min i-am spus sotului ca pe asta [...]
Question for Chandoo:
I came to your site late but am totally loving these challenges 🙂
I guess it all boils down to how the bins are set up.
I agree with the PERCENTILE.INC function.
pls help me understand where I am wrong.
I have determined following the bins:
bottom 5% <=2.00 (F6:F33 <=PERCENTILE(range,.05))
lower 15% (5+10) <= 2.40 (F6:F33 <=PERCENTILE(range,.15))
lower 80% (5+10+65) <=3.46 (F6:F33 <=PERCENTILE(range,.80))
lower 95% (5+10+65+15) <=4.00 (F6:F33 =PERCENTILE(range,.95))
top 5% <=4.20 (F6:F33 <=PERCENTILE(range,1.00))
I find that only Tom is highest scorer and unique top 5% achiever.
I notice that Chandoo has included Christy and Daniel in top 5% achievers. How can there be 3 people in top 5% out of a population of 28 (5% of 28 = 1.4, i.e. only one person can achieve that status)?
I tried different ways but cannot get to that distribution.
Rest of the work is simply organizing the conditional formatting rules with Stop If True box checked.
Thanks for your insights