The Science of Success - Cascadia Ruby 2014

Software is approached mainly from the angle of engineering. Let's step back and take a look at software as science. How can we increase the quality of our code, tune our minds to efficiently solve problems, and correctly reapply known solutions to new problems? Learn a few new tricks about how to easily benchmark your code and how to analyze code complexity.

Framed by the story of my own path from would-be Physicist to happy Software Engineer, let's look at using the scientific method as a guide for software development.

Transcript

1. The Science of Success Davy Stevenson @davystevenson Cascadia Ruby 2014
2. The Columbia River Gorge, Home by Paul Kline
3. Astronaut by Alan
4. Williams College by Ethan Kan
5. White, Mt Greylock by kumsval
6. In Search of the Abominable Snowman by Peter Lee
7. Fish Bowl Embroidery by Jenny S
8. light brain by Mario D’Amore
9. Cao Xueqin, Dream of the Red Chamber by Ivan Walsh
10. Modern Art in Prague by BrunoDelzant
11. Greek Philosopher Mosaic by Holly Hayes
12. Hacker by the Preiser Project
13. Glass of Heart by Rahim Packir Saibo
14. 100 Planetary Nebulas by Judy Schmidt
15. Professor John Frink, Jr. vs. Professor Hubert J. Farnsworth by JD Hancock
16. Complexity
17. Brockhaus and Efron Encyclopedic Dictionary
18. Complexity O(n) O(log n) O(n log n) O(n2) O(2n) O(n!)
19. Complexity O(log n) - Logarithmic - Sorted Data
20. Complexity O(n) - Linear - Analyze each point
21. Complexity O(n log n) - Loglinear Best Sorting Algorithms
22. Complexity O(n2) - Quadratic Compare pairs of points
23. Complexity O(2n) - Exponential - Try and avoid
24. Complexity O(n!) - Factorial You’re gonna have a bad time
25. Algorithms
26. Silver and Gold - Charles Babbage’s Difference Engine by odditty
27. jar by hillary.hc.chang
28. Convex Hull by fdecomite
29. Stonebalancing in Greece by t.klick
30. Jarvis March
31. Plejaden M45 by Carsten Frenzi
32. Plejaden M45 by Carsten Frenzi
33. Plejaden M45 by Carsten Frenzi
34. Plejaden M45 by Carsten Frenzi
35. Plejaden M45 by Carsten Frenzi
36. Plejaden M45 by Carsten Frenzi
37. Plejaden M45 by Carsten Frenzi
38. Plejaden M45 by Carsten Frenzi
39. Plejaden M45 by Carsten Frenzi
40. Plejaden M45 by Carsten Frenzi
41. Plejaden M45 by Carsten Frenzi
42. Jarvis March • Find one edge: O(n) • Find right-most point: O(n) • Repeat for each point on hull: O(h) • O(n + n * h) => O(n h) • Worst case: O(n2)
43. Monotone Chain
44. Plejaden M45 by Carsten Frenzi
45. 1 2 3 4 5 6 7 8 9 Plejaden M45 by Carsten Frenzi
46. 1 2 3 4 5 6 7 8 9 Plejaden M45 by Carsten Frenzi
47. 4 5 6 7 8 9 Plejaden M45 by Carsten Frenzi
48. 5 6 7 8 9 Plejaden M45 by Carsten Frenzi
49. 5 6 7 8 9 Plejaden M45 by Carsten Frenzi
50. 5 6 7 8 9 Plejaden M45 by Carsten Frenzi
51. 6 7 8 9 Plejaden M45 by Carsten Frenzi
52. 7 8 9 Plejaden M45 by Carsten Frenzi
53. 7 8 9 Plejaden M45 by Carsten Frenzi
54. 7 8 9 Plejaden M45 by Carsten Frenzi
55. 7 8 9 Plejaden M45 by Carsten Frenzi
56. 8 9 Plejaden M45 by Carsten Frenzi
57. 9 Plejaden M45 by Carsten Frenzi
58. 9 Plejaden M45 by Carsten Frenzi
59. Plejaden M45 by Carsten Frenzi
60. Plejaden M45 by Carsten Frenzi
61. Plejaden M45 by Carsten Frenzi
62. Plejaden M45 by Carsten Frenzi
63. Plejaden M45 by Carsten Frenzi
64. Monotone Chain • Sort points: O(n log n) • Construct lower hull: O(n) • Construct upper hull: O(n) • O(n log n + (n + n)) => O(n log n) • O(n) if already sorted
65. Pushpins in a map over the USA by Marc Levin
66. Benchmark
67. Fast by photophilde
68. require 'benchmark' n = 100_000 size = 10000 array = (0...size).to_a.shuffle ! Benchmark.bm do |x| x.report("#at") { n.times { array.at rand(size)} } x.report("#index") { n.times { array.index rand(size) } } x.report("#index-miss") { n.times { array.index (size + rand(size)) } } end
69. require 'benchmark' n = 100_000 size = 10000 array = (0...size).to_a.shuffle ! Benchmark.bm do |x| x.report("#at") { n.times { array.at rand(size)} } x.report("#index") { n.times { array.index rand(size) } } x.report("#index-miss") { n.times { array.index (size + rand(size)) } } end
70. require 'benchmark' n = 100_000 size = 10000 array = (0...size).to_a.shuffle ! Benchmark.bm do |x| x.report("#at") { n.times { array.at rand(size)} } x.report("#index") { n.times { array.index rand(size) } } x.report("#index-miss") { n.times { array.index (size + rand(size)) } } end
71. require 'benchmark' n = 100_000 size = 10000 array = (0...size).to_a.shuffle ! Benchmark.bm do |x| x.report("#at") { n.times { array.at rand(size)} } x.report("#index") { n.times { array.index rand(size) } } x.report("#index-miss") { n.times { array.index (size + rand(size)) } } end
72. require 'benchmark' n = 100_000 size = 10000 array = (0...size).to_a.shuffle ! Benchmark.bm do |x| x.report("#at") { n.times { array.at rand(size)} } x.report("#index") { n.times { array.index rand(size) } } x.report("#index-miss") { n.times { array.index (size + rand(size)) } } end
73. $ ruby examples/bm.rb user system total real #at 0.020000 0.000000 0.020000 ( 0.023444) #index 2.380000 0.000000 2.380000 ( 2.391208) #index-miss 4.770000 0.000000 4.770000 ( 4.786147)
74. $ ruby examples/bm.rb user system total real #at 0.020000 0.000000 0.020000 ( 0.023444) #index 2.380000 0.000000 2.380000 ( 2.391208) #index-miss 4.770000 0.000000 4.770000 ( 4.786147)
75. require 'benchmark' n = 100_000 size = 10000 array = (0...size).to_a.shuffle ! Benchmark.bm do |x| x.report("#at") { n.times { array.at rand(size)} } x.report("#index") { n.times { array.index rand(size) } } x.report("#index-miss") { n.times { array.index (size + rand(size)) } } end
76. require 'benchmark/ips' ! size = 10000 array = (0...size).to_a.shuffle ! Benchmark.ips do |x| x.report("#at") { array.at rand(size) } x.report("#index") { array.index rand(size) } x.report("#index-miss") { array.index (size + rand(size)) } x.compare! end
77. require 'benchmark/ips' ! size = 10000 array = (0...size).to_a.shuffle ! Benchmark.ips do |x| x.report("#at") { array.at rand(size) } x.report("#index") { array.index rand(size) } x.report("#index-miss") { array.index (size + rand(size)) } x.compare! end
78. $ ruby examples/ips.rb ! ! ! Calculating ------------------------------------- #at 79155 i/100ms #index 4039 i/100ms #index-miss 2055 i/100ms ------------------------------------------------- #at 3165995.2 (±10.7%) i/s - 15593535 in 5.006746s #index 41873.8 (±6.3%) i/s - 210028 in 5.040799s #index-miss 20592.7 (±7.5%) i/s - 102750 in 5.022168s ! Comparison: #at: 3165995.2 i/s #index: 41873.8 i/s - 75.61x slower #index-miss: 20592.7 i/s - 153.74x slower
79. $ ruby examples/ips.rb ! ! ! Calculating ------------------------------------- #at 79155 i/100ms #index 4039 i/100ms #index-miss 2055 i/100ms ------------------------------------------------- #at 3165995.2 (±10.7%) i/s - 15593535 in 5.006746s #index 41873.8 (±6.3%) i/s - 210028 in 5.040799s #index-miss 20592.7 (±7.5%) i/s - 102750 in 5.022168s ! Comparison: #at: 3165995.2 i/s #index: 41873.8 i/s - 75.61x slower #index-miss: 20592.7 i/s - 153.74x slower
80. $ ruby examples/ips.rb ! ! ! Calculating ------------------------------------- #at 79155 i/100ms #index 4039 i/100ms #index-miss 2055 i/100ms ------------------------------------------------- #at 3165995.2 (±10.7%) i/s - 15593535 in 5.006746s #index 41873.8 (±6.3%) i/s - 210028 in 5.040799s #index-miss 20592.7 (±7.5%) i/s - 102750 in 5.022168s ! Comparison: #at: 3165995.2 i/s #index: 41873.8 i/s - 75.61x slower #index-miss: 20592.7 i/s - 153.74x slower
81. $ ruby examples/ips.rb ! ! ! Calculating ------------------------------------- #at 79155 i/100ms #index 4039 i/100ms #index-miss 2055 i/100ms ------------------------------------------------- #at 3165995.2 (±10.7%) i/s - 15593535 in 5.006746s #index 41873.8 (±6.3%) i/s - 210028 in 5.040799s #index-miss 20592.7 (±7.5%) i/s - 102750 in 5.022168s ! Comparison: #at: 3165995.2 i/s #index: 41873.8 i/s - 75.61x slower #index-miss: 20592.7 i/s - 153.74x slower
82. $ ruby examples/ips.rb ! ! ! Calculating ------------------------------------- #at 79155 i/100ms #index 4039 i/100ms #index-miss 2055 i/100ms ------------------------------------------------- #at 3165995.2 (±10.7%) i/s - 15593535 in 5.006746s #index 41873.8 (±6.3%) i/s - 210028 in 5.040799s #index-miss 20592.7 (±7.5%) i/s - 102750 in 5.022168s ! Comparison: #at: 3165995.2 i/s #index: 41873.8 i/s - 75.61x slower #index-miss: 20592.7 i/s - 153.74x slower
83. $ ruby examples/ips.rb ! ! ! Calculating ------------------------------------- #at 79155 i/100ms #index 4039 i/100ms #index-miss 2055 i/100ms ------------------------------------------------- #at 3165995.2 (±10.7%) i/s - 15593535 in 5.006746s #index 41873.8 (±6.3%) i/s - 210028 in 5.040799s #index-miss 20592.7 (±7.5%) i/s - 102750 in 5.022168s ! Comparison: #at: 3165995.2 i/s #index: 41873.8 i/s - 75.61x slower #index-miss: 20592.7 i/s - 153.74x slower
85. Benchmark BigO
86. Benchmark Big O • github.com/davy/benchmark-bigo • Provides Big O notation benchmarking for Ruby
87. require 'benchmark/ips' ! size = 10000 array = (0...size).to_a.shuffle ! Benchmark.ips do |x| x.report("#at") { array.at rand(size) } x.report("#index") { array.index rand(size) } x.report("#index-miss") { array.index (size + rand(size)) } x.compare! end
88. require 'benchmark/bigo' ! Benchmark.bigo do |x| x.generate :array x.linear 2000 ! x.report("#at") {|array, size| array.at rand(size) } x.report("#index") {|array, size| array.index rand(size) } x.report("#index-miss") {|array, size| array.index (size + rand(size)) } x.chart! 'array.html' end
89. require 'benchmark/bigo' ! Benchmark.bigo do |x| x.generate :array x.linear 2000 ! x.report("#at") {|array, size| array.at rand(size) } x.report("#index") {|array, size| array.index rand(size) } x.report("#index-miss") {|array, size| array.index (size + rand(size)) } x.chart! 'array.html' end
90. require 'benchmark/bigo' ! Benchmark.bigo do |x| x.generate :array x.exponential ! x.report("#at") {|array, size| array.at rand(size) } x.report("#index") {|array, size| array.index rand(size) } x.report("#index-miss") {|array, size| array.index (size + rand(size)) } x.chart! 'array.html' end
91. require 'benchmark/bigo' ! Benchmark.bigo do |x| x.generate :array x.exponential ! x.report("#at") {|array, size| array.at rand(size) } x.report("#index") {|array, size| array.index rand(size) } x.report("#index-miss") {|array, size| array.index (size + rand(size)) } x.chart! 'array.html' end
92. require 'benchmark/bigo' ! Benchmark.bigo do |x| x.generate :array x.exponential ! x.report("#at") {|array, size| array.at rand(size) } x.report("#index") {|array, size| array.index rand(size) } x.report("#index-miss") {|array, size| array.index (size + rand(size)) } x.chart! 'array.html' end
93. $ ruby examples/bigo-exp.rb ! Calculating ------------------------------------- #at 1 68448 i/100ms #at 10 63310 i/100ms #at 100 67388 i/100ms #at 1000 65912 i/100ms #at 10000 65518 i/100ms #index 1 66714 i/100ms #index 10 63736 i/100ms #index 100 50055 i/100ms #index 1000 18838 i/100ms #index 10000 3752 i/100ms #index-miss 1 61960 i/100ms #index-miss 10 58333 i/100ms #index-miss 100 45989 i/100ms #index-miss 1000 14698 i/100ms #index-miss 10000 1898 i/100ms ------------------------------------------------- #at 1 2084640.3 (±9.5%) i/s - 10335648 in 5.029076s #at 10 2006228.2 (±8.3%) i/s - 9939670 in 5.003949s #at 100 1871633.1 (±18.1%) i/s - 8962604 in 5.025712s #at 1000 2055675.6 (±8.7%) i/s - 10216360 in 5.029822s #at 10000 2000566.4 (±8.6%) i/s - 9893218 in 4.999732s #index 1 1992529.4 (±8.2%) i/s - 9940386 in 5.035758s #index 10 1810344.6 (±8.3%) i/s - 8986776 in 5.012351s #index 100 1304666.0 (±9.2%) i/s - 6457095 in 5.010804s #index 1000 347986.2 (±6.0%) i/s - 1733096 in 5.002854s #index 10000 40728.2 (±10.7%) i/s - 202608 in 5.059052s #index-miss 1 1984727.2 (±9.4%) i/s - 9851640 in 5.028868s #index-miss 10 1762957.2 (±7.6%) i/s - 8749950 in 5.004258s #index-miss 100 986260.8 (±10.2%) i/s - 4874834 in 5.010465s #index-miss 1000 187159.1 (±7.9%) i/s - 940672 in 5.063904s #index-miss 10000 19330.9 (±12.8%) i/s - 94900 in 5.001322s
95. Map of Node coverage with Convex Hulls by Dario Villanueva
96. Terraformer
97. Terraformer Ruby • github.com/esripdx/terraformer-ruby • A geometric toolkit for dealing with geometry, geography, formats • Can calculate Convex Hull
98. Jarvis Tortoise by Alexander Montuschi
99. Run, bunny, run! by shadow planet Monotone
102. module Terraformer::Benchmark # portland LON = -122.6764 LAT = 45.5165 ! # calculate convex hull with given implementation def self.convex_hull obj, impl Terraformer::ConvexHull.impl = impl obj.convex_hull end end ! class Float def perm self + rand(-100..100) / 10000.0 end end
103. module Terraformer::Benchmark # portland LON = -122.6764 LAT = 45.5165 ! # calculate convex hull with given implementation def self.convex_hull obj, impl Terraformer::ConvexHull.impl = impl obj.convex_hull end end ! class Float def perm self + rand(-100..100) / 10000.0 end end
104. module Terraformer::Benchmark # portland LON = -122.6764 LAT = 45.5165 ! # calculate convex hull with given implementation def self.convex_hull obj, impl Terraformer::ConvexHull.impl = impl obj.convex_hull end end ! class Float def perm self + rand(-100..100) / 10000.0 end end
105. module Terraformer::Benchmark ! # generates a Line String representing a random walk def self.random_walk size walk = [[LON, LAT]] # start in pdx ! size.times do walk << walk.last.map{|i| i.perm } end ! # create line string from the random walk ls = Terraformer::LineString.new(walk) ! # convert to feature ls.to_feature end end
106. module Terraformer::Benchmark ! # generates a Line String representing a random walk def self.random_walk size walk = [[LON, LAT]] # start in pdx ! size.times do walk << walk.last.map{|i| i.perm } end ! # create line string from the random walk ls = Terraformer::LineString.new(walk) ! # convert to feature ls.to_feature end end
108. Benchmark.bigo do |x| x.generator {|size| Terraformer::Benchmark.random_walk size } ! x.time = 20 # sample each point for 20 seconds x.linear 200 x.increments = 5 # 200..1000 ! x.report("#rand-jarvis") {|f, _| Terraformer::Benchmark.convex_hull f, :jarvis_march } ! x.report("#rand-monotone") {|f, _| Terraformer::Benchmark.convex_hull f, :monotone} ! x.chart! 'data/chart_random_walk.html' x.compare! end
109. Benchmark.bigo do |x| x.generator {|size| Terraformer::Benchmark.random_walk size } ! x.time = 20 # sample each point for 20 seconds x.linear 200 x.increments = 5 # 200..1000 ! x.report("#rand-jarvis") {|f, _| Terraformer::Benchmark.convex_hull f, :jarvis_march } ! x.report("#rand-monotone") {|f, _| Terraformer::Benchmark.convex_hull f, :monotone} ! x.chart! 'data/chart_random_walk.html' x.compare! end
110. Benchmark.bigo do |x| x.generator {|size| Terraformer::Benchmark.random_walk size } ! x.time = 20 # sample each point for 20 seconds x.linear 200 x.increments = 5 # 200..1000 ! x.report("#rand-jarvis") {|f, _| Terraformer::Benchmark.convex_hull f, :jarvis_march } ! x.report("#rand-monotone") {|f, _| Terraformer::Benchmark.convex_hull f, :monotone} ! x.chart! 'data/chart_random_walk.html' x.compare! end
114. Water Balloon by Amyn Kassam
115. Water Balloon by Amyn Kassam
116. module Terraformer::Benchmark ! # generates a circle feature with size points def self.circle size ! # minimum size is three size = 3 if size < 3 ! # expand the diameter as size increases diam = [100, size].max ! # generate circle c = Terraformer::Circle.new([LON, LAT], diam, size) ! # convert to feature c.to_feature end end
117. module Terraformer::Benchmark ! # generates a circle feature with size points def self.circle size ! # minimum size is three size = 3 if size < 3 ! # expand the diameter as size increases diam = [100, size].max ! # generate circle c = Terraformer::Circle.new([LON, LAT], diam, size) ! # convert to feature c.to_feature end end
119. Benchmark.bigo do |x| x.generator {|size| Terraformer::Benchmark.circle size } ! x.time = 20 # sample each point for 20 seconds x.linear 200 x.increments = 5 # 200..1000 ! x.report("#circ-jarvis") {|f, _| Terraformer::Benchmark.convex_hull f, :jarvis_march } ! x.report("#circ-monotone") {|f, _| Terraformer::Benchmark.convex_hull f, :monotone} ! x.chart! 'data/chart_circle.html' x.compare! end
125. Benchmark Terraformer • github.com/davy/benchmark-terraformer • Helper code • Benchmark code • Map Viewer • Example charts, geojson & raw data • Array benchmark code
126. My grandfather's microscope by Juan Eduardo Donoso
127. Peer Review!
128. Line Fitting
129. Prettier Graphs
130. Verify Math
132. Science Driven Development
133. QUESTION
134. why is ____________ slow?
135. why is ____________ broken?
136. is ____________ a success?
137. HYPOTHESIS
138. it is slow because ___________
139. it is broken because ___________
140. it is successful because ___________
141. PREDICTION
142. if __________ is why it is slow then ____________
143. if __________ is why it is broken then ____________
144. if __________ is true then it is a success
145. TESTING
146. test the speed of ____________
147. test the logic of ____________
148. test if ____________ is true
149. ANALYSIS
150. what does the data say?
151. Fix
152. Sleeping Cat by Terence Lee
153. Scientist Minifig by Maia Weinstock
154. Thanks! Questions? Davy Stevenson @davystevenson Cascadia Ruby 2014
155. Resources Benchmark IPS - github.com/evanphx/benchmark-ips Benchmark BigO - github.com/davy/benchmark-bigo Terraformer.rb - github.com/esripdx/terraformer-ruby ! Benchmark Terraformer Results- github.com/davy/ benchmark-terraformer ! Maps by Leaflet - github.com/Leaflet/Leaflet extended with Esri Leaflet - github.com/Esri/esri-leaflet and Leaflet Ajax - github.com/calvinmetcalf/leaflet-ajax
156. Attributions From the Noun Project: ! “Erlenmeyer Flask” by Emily van den Heever “Stopwatch” by Irit Barzily “Diamond” by Ryan Beck “Question” by Brennan Novak “Check Mark” by Brennan Novak “Arrow” by José Campos
157. Attributions Backgrounds: Clouds by Joshua Rappeneker First Stars by Paul Chaloner grassy by cometwendy Drops on Bright Orange Flower by A Guy Taking Pictures Lightning by Stuart Williams Beach Palm Trees by Grand Velas Riviera Maya ! !