We all know that area charts are great for understanding how a list of values have changed over time. Today, let’s learn how to create an area chart that shows different colors for upward & downward movements.
The inspiration for this came from a recent chart published in Wall Street Journal about Chinese stock markets (shown below).
We will try to create a similar chart using Excel.
This is what we are going to come up with.
Looks interesting? Read on…
Creating an area chart with different colors for up & down slopes
Step 1. Gather the data
For our example, let’s use Indian stock market data for last 10 years. Specifically, BSE Sensex weekly closing prices between 1-July-2005 and 27-July-2015.
There are 3 columns in this data – Date, Closing price & Volume, as shown below. Let’s say all of this data is in a tabled named data that starts at cell B6.
Step 2. Find out when to switch colors
The next step is to find out when to switch colors.
We can add 3 additional columns to our data to spot the switches, and split data to Advances & Declines accordingly.
Here is what we get.
Detecting when a switch occurs:
When looking at closing price for a day, we need to know if the line direction has changed or not. To detect this, we can use a formula like this:
Assuming the closing price we are looking at is in cell C7,
=C7<>MEDIAN(C6:C8) will tell us if the value in C7 is switching the trend or not.
Why does this formula work? Think again. For more on this technique, refer to BETWEEN Formula in Excel.
Step 3. Expanding the data so that we can create an area chart
If we create an area chart with just the data from above step (only advances & declines columns), we end up with a chart that looks like this.
As you can see, the green & red areas (advancing & declining data) have tiny white space between them.
This is because, when we switch from green to red, the green series goes from peak to 0 and simultaneously, red series goes from 0 to peak, creating an effect like below (chart made from sub-set of data)
To create correct shading effect, we need to expand the data so that on dates when switching happens, there is a duplicate row.
See below illustration to understand what we need.
Writing formulas to expand data
We can use simple arithmetic along with healthy dose of INDEX formulas to create expanded data set. Can you figure out the formulas yourself as homework?
Please examine the downloadable workbook to understand these formulas more.
After expanding the data, the same area chart looks like this:
Step 4. Create area chart from expanded dataset
Select the expanded advances & declines columns and create an area chart from them. Make sure horizontal axis labels are pointing to the expanded date column we constructed in step 3.
Your chart is ready now.
We can add few more bells and whistles to it and come up with below output.
- The volume chart at the bottom is a sparkline
- We can find longest bull & bear rallies using longest winning streak formula
Download Area Chart with different colors for up & down slopes workbook
Please click here to download area chart with different colors workbook. Play with the chart & formulas to learn more.
How do you like area chart with different shades?
I think this is a powerful technique to quickly eye-ball data and see where directional changes are occurring, what patterns (if any) are they following etc.
If you observe carefully, our Excel version and WSJ’s charts differ in one key aspect. In WSJ chart, they are shading bull & bear markets where overall trend is upwards or downwards with minor changes during the market period. What formula / approach changes do you think are necessary to make exact replica of WSJ chart in Excel?
Also, do share your feedback about this chart and how you are planning to reuse the concepts at your work.
Addendum – Moving average based smoothing of trends
We can use simple moving averages to smooth the trends so that we can spot upward / downward movements better.
Here is an example chart.
You may download this workbook to examine the formulas & chart.
Charts to show change over time
Understanding change is a key component of any analysis. Check out below charting techniques & tutorials to learn few more valuable skills.
- Narrating the story of change – Case study on how fast America changes its mind
- Advances vs. Declines chart
- How tax burden has changed over years – interactive Excel chart
- Use indexed charts when analyzing change over time
- Never show simple numbers in your dashboards
- Comparing with benchmarks – shading under / over achievement
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.