Using Box Plots Differently

For those of us into performance consulting, Box plot (Know more about them here), is a wonderfully simple and efficient tool to help us get about our job. As every coin has two faces, every data-set has two aspects. One, is the "feel-good" part of it, the part which tells us about the successes and the top performers. Second, is the "ouch" bit of it, that gets us to notice the outliers.

Usually, the Box-and-Whisker diagram is used to plot and separate data as the smallest and largest values, the median, and the lower and the upper quartiles. But, the shape and the style of it can be applied to depict other sets of data as well. Here, I've used the B&W template to depict the monthly temperatures of my home city - Calcutta.

The necessary data was gathered from here and there. It included the data for record monthly highs and lows, which were depicted in the chart by the whiskers, and the average monthly range of normal temperature, which is represented by the box, and the average monthly temperature by the line. The maximum and the minimum temperature, of the months of a specific year, taken here as 2010, is represented as a range by the violet column to show its position vis-a-vis the Box and whisker graph.

The final look:

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The Playfair Charts: Scotland ExIm Barchart

Soon after finishing the second Playfair chart, the one on Wheat Price and Wages, I searched the internet for additional charts made by him. I found a Bar chart circa 1786, which showed the Scottish export and import volumes with other countries. For me, the real thrill was to scroll by the list of the name of places long consigned to history books - Jersey Is, Greenland, Prussia, Denmark and Norway (together) and Flanders. First, the original Playfair Barchart from Wikipedia, Then, my version of it in Excel. A couple of parting words: Excel 2007 no longer support dots and lines as fillers for charts. Hence, the ribbed import chart is given a different color, Gold. Normally, I'd use data point labels to construct the chart legends and other declarations given at the bottom of the chart. However, given Excel 2007' inability to automatically re-size labels to fit texts, I was forced to use text-boxes instead.

The Dorling Cartogram

My last project involved using a multitude of regions for drawing analysis, parallels and comparison. Not wanting to use yet another Choropleth graph, I decided to look up alternatives that were easier to create and preferably required no VBA. Soon I stumbled upon "The Dorling Cartogram", defined in the UCSB site as, "This type of cartogram was named after its inventor, Danny Dorling of the University of Leeds. A Dorling cartogram maintains neither shape, topology nor object centroids, though it has proven to be a very effective cartogram method. To create a Dorling cartogram, instead of enlarging or shrinking the objects themselves, the cartographer will replace the objects with a uniform shape, usually a circle, of the appropriate size." I had the data for Obesity in the United States handy, so I decided to give it a try before using it in my project. I opted to use Bubble charts because data points within a series may need to be of varied shapes based on...

The Playfair Charts: Wheat Price and Wages

After successfully recreating the Playfair trade-balance time-series chart , I took up the second chart shown in Jorge's post which is fancifully titled, "Chart showing at one view the price of the quarter of wheat and Wages of Labour by the week from The year 1565 to 1821." I left out the top arches. Comparatively, this was the easier chart. Staying true to Jorge' rules, I didn't use any shape or clipart objects in this chart. The big oval shaped object in the middle of the chart, which contains the title is actually a marker for a data point. The original Playfair Wheat price and Wages chart from Wikipedia, and underneath, is my version in Excel.

Somnath's Excel Charts

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