Luka Petrović 69/2012 1/12 • The Standard Deviation is a measure of how spread out numbers are. • Its symbol is σ (the greek letter sigma) • The formula is easy: it is the square root of the Variance. So now you ask, "What is the Variance?" 2/12 • The Variance is average of the squared differences from the Mean. • 3 simple steps to calculate the Variance: • 1. Calculate the Mean (the simple average of the numbers) 2. Then for each number: subtract the Mean and square the result 3. Then work out the average of (2) *Reminder: we will root this value to get Standard Deviation! 3/12 • You and your friends have just measured the heights of your dogs (in millimeters): • The heights (at the shoulders) are: 600mm, 470mm, 170mm, 430mm and 300mm. 4/12 • The mean (average) height is 394 mm. 5/12 • Now we calculate each dog's difference from the Mean: • • Then square them: Maxeler part 6/12 • And the Standard Deviation is just the square root of Variance: • Standard Deviation: σ = √21,704 = 147.32... = 147 (to the nearest mm) 7/12 • Now, we will do this using Maxeler… 8/12 • Kernel code • Final graph 9/12 • Correct execution! • Data: Random float values in range 0-100 • Running on MaxCompilerVM-2015, MaxIDE (Eclipse for Maxeler) 10/12 • Milutinovic, V., et al, Guide to DataFlow SuperComputing, Springer, 2015. • Milutinovic, V., editor, Advances in Computers: DataFlow, Elsevier, 2015. • Milutinovic, V. et al, Paradigm Shift in SuperComputing: DataFlow vs ControlFlow, Journal of Big Data, 2015 • http://www.mathsisfun.com/ • http://www.wikipedia.org/ • http://www.investopedia.com/terms/s/standarddeviation.asp 11/12 • Maxeler is fun and we hope we will get more of these: 1. Tutorials 2. Development tools 3. Community help 12/12