visualisation 2012 - 2013 lecture 3
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Visualisation 2012 - 2013 Lecture 3. Visualising Trends. Brian Mac Namee Dublin institute of Technology Applied Intelligence Research Centre. Origins. This course is based heavily on a course developed by Colman McMahon ( www.colmanmcmahon.com ) - PowerPoint PPT PresentationTRANSCRIPT
Visualisation2012 - 2013
Lecture 3
Brian Mac NameeDublin institute of Technology
Applied Intelligence Research Centre
Visualising Trends
OriginsThis course is based heavily on a course developed by Colman McMahon (www.colmanmcmahon.com)Material from multiple other online and published sources is also used and when this is the case full citations will be given
22011/12
Visualization of the Week
www.pinterest.com/brianmacnamee/great-visualisation-examples/
(Un)Visualization of the Week
www.pinterest.com/brianmacnamee/terrible-visualisation-examples/
AgendaVisualising patterns over timeDiscrete points in timeContinuous points in timeHandling multiple dimensions over time
52011/12
What To Look ForThe most common thing you look for in time series, or temporal, data is trends
- Is something increasing or decreasing? - Are there seasonal cycles?
To find these patterns, you have to look beyond individual data points to get the whole picture
2011/12 7
Visualising Patterns Over Time
Visualising patterns over time
- Discrete points in time
• Bar Graph
• Scatter Plot- Continuous points
in time• Line Chart
• Step Chart- Handling multiple
dimensions over time
• Stacked Bar Chart
• Area Chart
• Stream Graph
• Small Multiples
• Animation2011/12 8
Discrete Points In Time
Often we have datasets that contain single measurements for a reasonably small number of discrete points in time
- Profit per year- Rainfall per month
In these cases a simple bar graph is often appropriate
Simple Bar Graph
“Visualize This”, N. Tau, Wiley, 2011 http://shop.oreilly.com/product/0636920022060.do
Simple Bar Graph
“Visualize This”, N. Tau, Wiley, 2011 http://shop.oreilly.com/product/0636920022060.do
Simple Bar Graph
http://www.mornpen.vic.gov.au/page/imageThumbnail.asp?C_Id=820
Continuous Points In Time
Often we have datasets that contain single measurements for a number of continuous points of time
- Stock prices over time- Internet traffic over time
In these cases a line charts are more appropriate
Simple Scatter Plot
2011/12 14“Visualize This”, N. Tau, Wiley, 2011
http://shop.oreilly.com/product/0636920022060.do
Simple Scatter Plot
“Visualize This”, N. Tau, Wiley, 2011 http://shop.oreilly.com/product/0636920022060.do
Simple Line ChartSimply adding a line to a scatter plot can help greater emphasise a trend over time
“Visualize This”, N. Tau, Wiley, 2011 http://shop.oreilly.com/product/0636920022060.do
Simple Line Chart
“Visualize This”, N. Tau, Wiley, 2011 http://shop.oreilly.com/product/0636920022060.do
Simple Line Chart
“Visualize This”, N. Tau, Wiley, 2011 http://shop.oreilly.com/product/0636920022060.do
Step ChartBasic line charts interpolate the change in measurement from one point in time to anotherOften this is not appropriate and in these cases step charts are more appropriate
“Visualize This”, N. Tau, Wiley, 2011 http://shop.oreilly.com/product/0636920022060.do
Step Chart
2011/12 20“Visualize This”, N. Tau, Wiley, 2011
http://shop.oreilly.com/product/0636920022060.do
Step Chart
“Visualize This”, N. Tau, Wiley, 2011 http://shop.oreilly.com/product/0636920022060.do
Fitting A LineIn some cases adding a line to a scatter plot can mask the trend over time rather than help illustrate itIn this cases it can be more appropriate to fit a line or curve to a dataset so as to highlight a trend in timeACHTUNG: Be careful when fitting lines, it is possible to illustrate trends that don’t really exist
Fitting A Line
“Visualize This”, N. Tau, Wiley, 2011 http://shop.oreilly.com/product/0636920022060.do
Smoothing & Estimation
2011/12 24“Visualize This”, N. Tau, Wiley, 2011
http://shop.oreilly.com/product/0636920022060.do
Multiple Dimensions In Time
Often we have datasets that contain multiple measurement for each point in time which gives us multiple dimensionsThis makes visualization more challenging as we need to use newer and different encodingsThere are a number of approaches we can take
Stacked Bar Chart
“Visualize This”, N. Tau, Wiley, 2011 http://shop.oreilly.com/product/0636920022060.do
Stacked Bar Chart
Charting U.S. Gun Manufacturing, Matt Stiles, The Daily Viz, 2012http://thedailyviz.com/2012/08/07/charting-u-s-gun-manufacturing/
Stacked Bar ChartInterpreting multiple time series in a stacked bar chart can be really difficult, especially when we need to interpret the trend within the higher categoriesOnly really appropriate when the real trend we want to illustrate is the overall total bar height trend and the individual categories are secondary
Multiple Line Series
http://hci.stanford.edu/jheer/files/zoo/ex/time/index-chart.html
Multiple Line Series
Displaying time-series data: Stacked bars, area charts or lines…you decide!, VizWiz, 2012http://vizwiz.blogspot.ie/2012/08/displaying-time-series-data-stacked.html
U.S. Gun Manufacturing By Type
Stacked Area Chart
“Visualize This”, N. Tau, Wiley, 2011 http://shop.oreilly.com/product/0636920022060.do
Stacked Area ChartU.S. Gun Manufacturing By Type
Displaying time-series data: Stacked bars, area charts or lines…you decide!, VizWiz, 2012http://vizwiz.blogspot.ie/2012/08/displaying-time-series-data-stacked.html
Stacked Area ChartStacked area charts unfortunately suffer from many of the same problems as stacked bar chartsIt can be very hard to interpret the trends of each category as they are stacked on top of each other
Stacked Area Chart
Displaying time-series data: Stacked bars, area charts or lines…you decide!, VizWiz, 2012http://vizwiz.blogspot.ie/2012/08/displaying-time-series-data-stacked.html
What does the shotgun trend look like?
Stacked Area Chart
Displaying time-series data: Stacked bars, area charts or lines…you decide!, VizWiz, 2012http://vizwiz.blogspot.ie/2012/08/displaying-time-series-data-stacked.html
Stream GraphThe Stream Graph is an attempt to overcome the difficulties associated with stacked bar charts and stacked area charts
Stream Graph
ThemeRiver: Visualizing Theme Changes over Time, Susan Havre , Beth Hetzler , Lucy Nowell, Proc. IEEE Symposium on Information Visualization, 2000.
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.135.4974
Stream Graph
ThemeRiver: Visualizing Theme Changes over Time, Susan Havre , Beth Hetzler , Lucy Nowell, Proc. IEEE Symposium on Information Visualization, 2000.
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.135.4974
Stream Graph
Stacked Graphs – Geometry & Aesthetics, Lee Byron & Martin Wattenberg, 2008.http://www.leebyron.com/what/lastfm/
Stream Graph
Stacked Graphs – Geometry & Aesthetics, Lee Byron & Martin Wattenberg, 2008.http://www.leebyron.com/what/lastfm/
Stream Graph
Stacked Graphs – Geometry & Aesthetics, Lee Byron & Martin Wattenberg, 2008.http://www.leebyron.com/what/lastfm/
Stream Graph
http://hci.stanford.edu/jheer/files/zoo/ex/time/stack.html
The Ebb and Flow of Movies: Box Office Receipts 1986 — 2008, New York Timeshttp://www.nytimes.com/interactive/2008/02/23/movies/20080223_REVENUE_GRAPHIC.html
Stream Graph
Small MultiplesOne solution to illustrating time is to use small multiples to show multiple snapshots of the data at different points in time
Small Multiples
http://hci.stanford.edu/jheer/files/zoo/ex/time/multiples.html
Small Multiples
Small Multiples
Tres Epistolae de Maculis Solaribus Scriptae ad Marcum Welserum, Christoph Scheiner, 1612http://galileo.rice.edu/sci/observations/sunspots.html
AnimationAnimation is obviously a great way to illustrate changes over timeWe will look at this more later in the course
Animation
www.ted.com/talks/hans_rosling_shows_the_best_stats_you_ve_ever_seen.html
Animation
Galileo's Sunspot Drawingshttp://galileo.rice.edu/sci/observations/ssm_slow.mpg
Gallileo made flip books of sunspot images to show how they moved over time
ConclusionsVisualising across time is a key methodologyThere are a number of approaches that are common and usefulWe will come back to animation