Upgrade to Pro — share decks privately, control downloads, hide ads and more …

RailsConf 2017

RailsConf 2017

It's my keynote from RailsConf 2017

Aaron Patterson

May 05, 2017
Tweet

More Decks by Aaron Patterson

Other Decks in Programming

Transcript

  1. View Slide

  2. Hello ICON!

    View Slide

  3. Hello RailsConf!

    View Slide

  4. View Slide

  5. Hi, I’m @tenderlove

    View Slide

  6. View Slide

  7. h
    GitHub

    View Slide

  8. Le Git

    View Slide

  9. Le Gîte Hub

    View Slide

  10. Rails Core Team

    View Slide

  11. Ruby Core Team

    View Slide

  12. View Slide

  13. View Slide

  14. View Slide

  15. I have stickers!

    View Slide

  16. View Slide

  17. View Slide

  18. View Slide

  19. View Slide

  20. "Why Slack is inappropriate for
    open source communications"

    View Slide

  21. "We are, temporarily, in a kind
    of dark ages of end-user open
    source software."

    View Slide

  22. Oops, I died of plague
    This is a rat

    View Slide

  23. Electron is flash for the
    desktop

    View Slide

  24. "slack often idles at 5% CPU
    usage"

    View Slide

  25. CPU
    Slack

    View Slide

  26. "Buy a bigger CPU, ya dummy"

    View Slide

  27. Alan Turning

    View Slide

  28. HN on Language Features

    View Slide

  29. "No generics and no sum types?
    Those are no longer groundbreaking,
    they're the bare minimum.*"
    *Emphasis not mine

    View Slide

  30. No generics means your
    language is a failure

    View Slide

  31. Insurance companies only
    cover Generics

    View Slide

  32. Sorry, your
    language has been
    denied
    L'Hôpital

    View Slide

  33. View Slide

  34. View Slide

  35. #supportlocal

    View Slide

  36. Local Coffee!

    View Slide

  37. Local Tea!

    View Slide

  38. Trolling DHH:
    An Annual Tradition

    View Slide

  39. View Slide

  40. View Slide

  41. Faith Based Programmer

    View Slide

  42. "Pleaseworkpleaseworkpleas
    eworkpleaseworkpleasework"
    The Programmer’s Prayer

    View Slide

  43. View Slide

  44. View Slide

  45. 24 bit audio

    View Slide

  46. 10+ Years of Rails

    View Slide

  47. It was the year 2003

    View Slide

  48. View Slide

  49. What should I do with all this
    free time?

    View Slide

  50. "We’ve tried to charge your
    card hundreds of times"

    View Slide

  51. Technical Debt

    View Slide

  52. Developers want to pay off
    technical debt

    View Slide

  53. Managers do not want to
    pay off technical debt
    (if they can help it)

    View Slide

  54. Tech Debt
    Gem Gem
    Gem
    Gem
    Gem
    Meta Gem

    View Slide

  55. Tech Debt
    Gem Gem
    Gem
    Gem
    Gem
    "Bond"
    "Tranche"

    View Slide

  56. Tech Debt
    Gem Gem
    Gem
    Webpack
    Gem
    Rails

    View Slide

  57. Blood of
    young people

    View Slide

  58. Concatenating a bunch of
    strings

    View Slide

  59. View Slide

  60. View Slide

  61. View Slide

  62. Not a Joke

    View Slide

  63. 5

    View Slide

  64. 5

    View Slide

  65. $5

    View Slide

  66. View Slide

  67. 5.1

    View Slide

  68. Rails 5.1 is out!

    View Slide

  69. Thanks @rafaelfranca!!!

    View Slide

  70. I don’t have time for this
    Things I don’t have time for but would like to do

    View Slide

  71. Non-committal

    View Slide

  72. Humorous use of common
    phrase

    View Slide

  73. "No Pressure"

    View Slide

  74. ALL OF THE
    PRESSURE

    View Slide

  75. Searls - Briggs

    View Slide

  76. STRESS

    View Slide

  77. Fear & Self Doubt

    View Slide

  78. 5 things I don’t have time
    to do
    but you should do them for me

    View Slide

  79. What if I don’t have time to
    present 5 things??

    View Slide

  80. What if I want to talk about
    things I do have time for?

    View Slide

  81. Some things I don’t have
    time to do
    but you should do them for me
    Maybe like 3 things?

    View Slide

  82. Probably Important
    Definitely Not Important

    View Slide

  83. HTTP/2 + Rack
    A thing that I do have time for

    View Slide

  84. What is HTTP/2?

    View Slide

  85. 1 better than HTTP/1

    View Slide

  86. 0.9 better than HTTP/1.1

    View Slide

  87. HTTP/2 (really)
    • Binary protocol
    • Multiplexes (multiple requests on the same socket)
    • Secure (only works over SSL*)
    • Push responses

    View Slide

  88. Push Response Flow

    View Slide

  89. HTTP 1.1
    Time
    index.html
    jquery.js
    gorby.css
    Client Server

    View Slide

  90. HTTP 2
    Time
    index.html
    jquery.js
    gorby.css
    Client Server

    View Slide

  91. Save Time by Pushing
    "Needed" Resources

    View Slide

  92. H2 Problems

    View Slide

  93. H2 is still stateless

    View Slide

  94. HTTP 2
    Time
    index.html
    jquery.js
    gorby.css
    Client Server

    View Slide

  95. Double Assets
    • Client can cancel (requires round trip)
    • Resend assets (extra bandwidth)

    View Slide

  96. Solution: H2O + SALT
    Get it, "solution"????

    View Slide

  97. Solution: H2O + Cookies

    View Slide

  98. What is H2O?
    https://h2o.examp1e.net

    View Slide

  99. Server (Unicorn)
    Proxy (h2o)
    Client
    HTTP/2 HTTP/1.1

    View Slide

  100. H2 Pushes with HTTP/1.1

    View Slide

  101. Link Header
    200 OK
    Content-Length: 1024
    Content-Type: text/html
    Link: ; rel=preload
    Link: ; rel=preload
    response body

    View Slide

  102. Server (Unicorn)
    Proxy (h2o)
    Client
    HTTP/2 HTTP/1.1
    200 OK
    Content-Length: 1024
    Content-Type: text/html
    Link: ; rel=preload
    Link: ; rel=preload
    response body

    View Slide

  103. No state tracking in the app

    View Slide

  104. Link Header Problem
    200 OK
    Content-Length: 1024
    Content-Type: text/html
    Link: ; rel=preload
    Link: ; rel=preload
    response body

    View Slide

  105. 103 Early Hints

    View Slide

  106. 103 Early Response
    103 Early Hints
    Link: ; rel=preload
    Link: ; rel=preload
    200 OK
    Content-Length: 1024
    Content-Type: text/html
    response body

    View Slide

  107. Rack Support
    Rack 3.0

    View Slide

  108. New ENV hash key! ("yay")
    env['rack.push'].call(103, [
    ['Link', '/gorby.css']
    ], [])

    View Slide

  109. Backwards Compatibility

    View Slide

  110. Graceful Upgrade

    View Slide

  111. Rack 3.0

    View Slide

  112. This is a talk about code
    smells

    View Slide

  113. Data I acquired (crap data)
    -100
    925
    1950
    2975
    4000
    Time
    2017-01-23
    15:53:51
    2017-01-23
    15:53:56
    2017-01-23
    15:54:01
    2017-01-23
    15:54:06
    2017-01-23
    15:54:11
    2017-01-23
    15:54:16
    2017-01-23
    15:54:21
    2017-01-23
    15:54:26
    2017-01-23
    15:54:31
    2017-01-23
    15:54:37
    2017-01-23
    15:54:42
    2017-01-23
    15:54:47
    2017-01-23
    15:54:52
    2017-01-23
    15:54:57
    2017-01-23
    15:55:02
    2017-01-23
    15:55:07
    2017-01-23
    15:55:12
    2017-01-23
    15:55:17
    2017-01-23
    15:55:22
    2017-01-23
    15:55:27
    2017-01-23
    15:55:32

    View Slide

  114. Ruby VM Tricks

    View Slide

  115. How a VM works

    View Slide

  116. VM
    [push, 4]
    [push, 3]
    [add]
    PC
    Program Stack
    4
    3
    7

    View Slide

  117. Implementation
    instructions = [
    [:push, 3],
    [:push, 7],
    [:add],
    ]
    pc = 0
    loop do
    instruction = instructions[pc]
    pc += 1
    send function_table[instruction.first]
    end

    View Slide

  118. Generate the VM

    View Slide

  119. Loop Elimination
    instructions = [ [:push, 3], [:push, 7], [:add], ]
    def push_op pc, val, instructions
    # code to push on the stack
    # ....
    next_instruction = instructions[pc]
    send(function_table[next_instruction.first]
    pc + 1,
    next_instruction,
    instructions)
    end
    def add pc, val, instructions
    # code to add
    # ....
    next_instruction = instructions[pc]
    send(function_table[next_instruction.first]
    pc + 1,
    next_instruction,
    instructions)
    end
    # start of VM
    pc = 0
    instruction = instructions[pc]
    pc += 1
    send function_table[instruction.first]
    Generated

    View Slide

  120. Threaded VM

    View Slide

  121. Function call elimination

    View Slide

  122. Function Name Lookup Table
    instructions = [ [:push, 3], [:push, 7], [:add], ]
    function_table = {
    :push => :push_op,
    :add => :add_op,
    }
    def push_op pc, val, instructions
    # code to push on the stack
    # ....
    next_instruction = instructions[pc]
    send(function_table[next_instruction.first]
    pc + 1,
    next_instruction,
    instructions)
    end

    View Slide

  123. JUMP
    instructions = [ [:push, 3], [:push, 7], [:add], ]
    function_table = {
    :push => ADDRESS_OF(:push_op),
    :add => ADDRESS_OF(:add_op),
    }
    label: :add_op
    # code to add
    # ...
    next_instruction = instructions[pc]
    val = next_instruction.drop(1)
    address = function_table[next_instruction.first]
    pc += 1
    GOTO(address)
    label: :push_op
    # code to push on the stack
    # ....
    next_instruction = instructions[pc]
    val = next_instruction.drop(1)
    address = function_table[next_instruction.first]
    pc += 1
    GOTO(address)
    Generated

    View Slide

  124. Lookup Table Elimination

    View Slide

  125. Addresses in Byte Code
    instructions = [
    [ADDRESS_OF(:push_op), 3],
    [ADDRESS_OF(:push_op), 7],
    [ADDRESS_OF(:add)],
    ]
    label: :add_op
    # code to add
    # ...
    next_instruction = instructions[pc]
    val = next_instruction.drop(1)
    address = next_instruction.first
    pc += 1
    GOTO(address)
    label: :push_op
    # code to push on the stack
    # ....
    next_instruction = instructions[pc]
    val = next_instruction.drop(1)
    address = next_instruction.first
    pc += 1
    GOTO(address)

    View Slide

  126. Direct Threaded VM

    View Slide

  127. Addresses are just integers

    View Slide

  128. MRI’s VM is Direct Threaded

    View Slide

  129. Create custom instructions built
    from machine code
    at runtime

    View Slide

  130. Extremely Simple Code
    require 'lolvm'
    class MyRuby
    attr_reader :rb_path2class, :rb_define_method, :mod
    def initialize ctx
    @mod = ctx.create_module 'ruby'
    @ctx = ctx
    init_functions
    end
    private
    def init_functions
    @rb_path2class = make_func('rb_path2class', @ctx.int8.pointer, [@ctx.int8.pointer])
    @rb_define_method = make_func('rb_define_method', @ctx.int8.pointer, [@ctx.int8.pointer, @ctx.int8.pointer, @ctx.int8.pointer, @ctx.int32])
    end
    def make_func name, ret, args
    func_type = LOLVM::Types::Function.new(ret, args, false)
    @mod.add_function name, func_type
    end
    end
    context = LOLVM::Context.instance
    builder = context.create_builder
    ruby = MyRuby.new context
    mod = context.create_module 'anon mod'
    func_type = LOLVM::Types::Function.new(context.double, [], false)
    testing = mod.add_function "testing", LOLVM::Types::Function.new(context.int64, [context.int8.pointer], false)
    testing.param(0).name = "foo"
    bb = context.append_basic_block testing, "entry"
    x = mod.add_global context.int64, 'rb_cObject'
    x.linkage = LOLVM::Linkages::External
    builder.position_at_end_of bb
    builder.ret builder.load x, "obj"
    func = mod.add_function "__anon", func_type
    bb = context.append_basic_block func, "entry"
    builder.position_at_end_of bb
    str = builder.global_string "MyRuby", 'string'
    func_name = builder.global_string "testing", 'func_name'
    my_ruby = builder.call testing, [str], 'rb_str'
    builder.ret my_ruby
    ee = mod.execution_engine
    ee.add_module ruby.mod
    p :GOT => ee.run("__anon")
    Assembles machine code
    at run time using LLVM

    View Slide

  131. Idea 1: Custom Instructions
    at Runtime

    View Slide

  132. Data I acquired (crap data)
    -100
    925
    1950
    2975
    4000
    Time
    2017-01-23
    15:53:51
    2017-01-23
    15:53:56
    2017-01-23
    15:54:01
    2017-01-23
    15:54:06
    2017-01-23
    15:54:11
    2017-01-23
    15:54:16
    2017-01-23
    15:54:21
    2017-01-23
    15:54:26
    2017-01-23
    15:54:31
    2017-01-23
    15:54:37
    2017-01-23
    15:54:42
    2017-01-23
    15:54:47
    2017-01-23
    15:54:52
    2017-01-23
    15:54:57
    2017-01-23
    15:55:02
    2017-01-23
    15:55:07
    2017-01-23
    15:55:12
    2017-01-23
    15:55:17
    2017-01-23
    15:55:22
    2017-01-23
    15:55:27
    2017-01-23
    15:55:32

    View Slide

  133. Build a Police Scanner

    View Slide

  134. View Slide

  135. Software Defined Radio

    View Slide

  136. View Slide

  137. FM Band

    View Slide

  138. Narrow FM
    Digital Trunking
    signal
    Audio

    View Slide

  139. Digital Signal Processing

    View Slide

  140. Continuous / Discrete
    Very Discrete
    tenderlove

    View Slide

  141. Discrete signals are just a list
    of points

    View Slide

  142. Discrete Signal (crap data)
    -100
    925
    1950
    2975
    4000
    Time
    2017-01-23
    15:53:51
    2017-01-23
    15:53:56
    2017-01-23
    15:54:01
    2017-01-23
    15:54:06
    2017-01-23
    15:54:11
    2017-01-23
    15:54:16
    2017-01-23
    15:54:21
    2017-01-23
    15:54:26
    2017-01-23
    15:54:31
    2017-01-23
    15:54:37
    2017-01-23
    15:54:42
    2017-01-23
    15:54:47
    2017-01-23
    15:54:52
    2017-01-23
    15:54:57
    2017-01-23
    15:55:02
    2017-01-23
    15:55:07
    2017-01-23
    15:55:12
    2017-01-23
    15:55:17
    2017-01-23
    15:55:22
    2017-01-23
    15:55:27
    2017-01-23
    15:55:32

    View Slide

  143. Convolution

    View Slide

  144. Signal Convolution
    -100
    925
    1950
    2975
    4000
    Time
    2017-01-23
    15:53:51
    2017-01-23
    15:54:01
    2017-01-23
    15:54:11
    2017-01-23
    15:54:21
    2017-01-23
    15:54:31
    2017-01-23
    15:54:42
    2017-01-23
    15:54:52
    2017-01-23
    15:55:02
    2017-01-23
    15:55:12
    2017-01-23
    15:55:22
    2017-01-23
    15:55:32
    0
    0.25
    0.5
    0.75
    1
    0 1 2 3 4 5 6 7
    * =?

    View Slide

  145. Formal Definition

    View Slide

  146. X
    -1.5
    -0.5
    0.5
    1.5
    0 1 2 3 4 5 6 7 8
    H
    -0.5
    0
    0.5
    1
    3 2 1 0
    Y
    -1.5
    0
    1.5
    3
    0 1 2 3 4 5 6 7 8 9 10 11

    View Slide

  147. Convolution Code
    def convolve x, h
    Array.new(x.length + h.length - 1) do |i|
    h.map.with_index { |h_j, j|
    if i - j < 0 || i - j > x.length - 1
    0
    else
    h_j * x[i - j]
    end
    }.inject(:+)
    end
    end

    View Slide

  148. Convolved Signal Length:
    x.length + h.length - 1

    View Slide

  149. X
    -1.5
    -0.5
    0.5
    1.5
    0 1 2 3 4 5 6 7 8
    H
    -0.5
    0
    0.5
    1
    3 2 1 0
    x
    + y[i] value

    View Slide

  150. Low Pass Filters

    View Slide

  151. Identity Signal
    X
    -1.5
    -0.5
    0.5
    1.5
    0 1 2 3 4 5 6 7 8
    H
    0
    0.25
    0.5
    0.75
    1
    0 1 2 3
    * =
    Y
    -1.5
    -0.5
    0.5
    1.5
    0 1 2 3 4 5 6 7 8 9 10 11

    View Slide

  152. Amplifier
    X
    -1.5
    -0.5
    0.5
    1.5
    0 1 2 3 4 5 6 7 8
    H
    0
    0.5
    1
    1.5
    2
    0 1 2 3
    * =
    Y
    -3
    -1
    1
    3
    0 2 4 6 8 10

    View Slide

  153. Shift
    X
    -1.5
    -0.5
    0.5
    1.5
    0 1 2 3 4 5 6 7 8
    H
    0
    0.25
    0.5
    0.75
    1
    0 1 2 3
    * =
    Y
    -1.5
    -0.5
    0.5
    1.5
    0 1 2 3 4 5 6 7 8 9 10 11

    View Slide

  154. Echo
    X
    -1.5
    -0.5
    0.5
    1.5
    0 1 2 3 4 5 6 7 8
    H
    0
    0.5
    1
    1.5
    2
    0 1 2 3
    * =
    Y
    -3.75
    -1.25
    1.25
    3.75
    0 1 2 3 4 5 6 7 8 9 10 11

    View Slide

  155. Average
    X
    -1.5
    -0.5
    0.5
    1.5
    0 1 2 3 4 5 6 7 8
    H
    0
    0.25
    0.5
    0.75
    1
    0 1 2 3
    * H
    0
    0.125
    0.25
    0.375
    0.5
    0 1 2 3
    *

    View Slide

  156. Radar

    View Slide

  157. Radar
    Transmission
    0
    25
    50
    75
    100
    Reception
    -25
    0
    25
    50
    75
    100

    View Slide

  158. Does one signal contain the
    other?

    View Slide

  159. received * transmitted
    Detection
    -10000
    0
    10000
    20000
    30000
    40000

    View Slide

  160. Gaussian Distribution

    View Slide

  161. Self Convolution
    signal = 100.times.map { rand }
    3.times do
    signal = convolve signal, signal
    end

    View Slide

  162. Self Convolution
    Gaussian Distribution
    0
    75000000000
    150000000000
    225000000000
    300000000000
    Neat!
    tenderlove

    View Slide

  163. Convolution Code
    def convolve x, h
    Array.new(x.length + h.length - 1) do |i|
    h.map.with_index { |h_j, j|
    if i - j < 0 || i - j > x.length - 1
    0
    else
    h_j * x[i - j]
    end
    }.inject(:+)
    end
    end

    View Slide

  164. My Signal

    View Slide

  165. R, the hard way

    View Slide

  166. Arrays are 1 based
    > data > data[0]
    numeric(0)
    > data[0] + 1
    numeric(0)
    >

    View Slide

  167. There must be an
    easier way!
    tenderlove

    View Slide

  168. Data I acquired (crap data)
    -100
    925
    1950
    2975
    4000
    Time
    2017-01-23
    15:53:51
    2017-01-23
    15:53:56
    2017-01-23
    15:54:01
    2017-01-23
    15:54:06
    2017-01-23
    15:54:11
    2017-01-23
    15:54:16
    2017-01-23
    15:54:21
    2017-01-23
    15:54:26
    2017-01-23
    15:54:31
    2017-01-23
    15:54:37
    2017-01-23
    15:54:42
    2017-01-23
    15:54:47
    2017-01-23
    15:54:52
    2017-01-23
    15:54:57
    2017-01-23
    15:55:02
    2017-01-23
    15:55:07
    2017-01-23
    15:55:12
    2017-01-23
    15:55:17
    2017-01-23
    15:55:22
    2017-01-23
    15:55:27
    2017-01-23
    15:55:32

    View Slide

  169. Implementing cons, car,
    and cdr in many languages
    (using only lambdas)

    View Slide

  170. Why?

    View Slide

  171. I like learning new languages

    View Slide

  172. But I don’t have much time

    View Slide

  173. Bare minimum to get
    endorsed on Linked In
    Do people still use Klout?

    View Slide

  174. What are cons, car, and cdr?

    View Slide

  175. cons forms a cell
    L R

    View Slide

  176. car returns the left side
    L R

    View Slide

  177. cdr returns the right side
    L R

    View Slide

  178. Only Lambdas?

    View Slide

  179. cons
    tenderlove.cons function(m) { m(x, y) }
    }
    R
    Node
    cons = ->(x, y) {
    ->(m) { m.(x, y) }
    }
    Ruby
    var cons = function(x, y) {
    return function(m) { return m(x, y); };
    }

    View Slide

  180. car
    tenderlove.car z(function(p, q) { p })
    }
    R
    var car = function(z) {
    return z(function(p, q) { return p; });
    }
    Node
    car = ->(z) {
    z.(->(p, q) { p })
    }
    Ruby

    View Slide

  181. Usage
    > tenderlove.cons(1, 2)
    function(m) { m(x, y) }

    > tenderlove.car
    function(z) { z(function(p, q) { p }) }
    > tenderlove.car(tenderlove.cons(1, 2))
    [1] 1
    >

    View Slide

  182. cdr
    tenderlove.cdr z(function(p, q) { q })
    }
    R
    var cdr = function(z) {
    return z(function(p, q) { return q; });
    }
    Node
    cdr = ->(z) {
    z.(->(p, q) { q })
    }
    Ruby

    View Slide

  183. Tree of Cells
    1
    2
    3 NUL

    View Slide

  184. each
    tenderlove.each if (!is.null(lst)) {
    element func(element)
    tenderlove.each(func, tenderlove.cdr(lst))
    }
    }
    R
    Node
    each = ->(func, list) {
    if list
    element = car.(list)
    func.(element)
    each.(func, cdr.(list))
    end
    }
    Ruby
    var each = function(func, list) {
    if(list) {
    element = car(list);
    func(element);
    each(func, cdr(list));
    }
    }

    View Slide

  185. Usage
    var each = function(func, list) {
    if(list) {
    element = car(list);
    func(element);
    each(func, cdr(list));
    }
    }
    each(console.log, cons(1, (cons(2, cons(3, null)))));
    [[email protected] dsp (master)]$ node dsp.js
    1
    2
    3
    [[email protected] dsp (master)]$

    View Slide

  186. Don’t need loops

    View Slide

  187. Don’t need arrays

    View Slide

  188. Don’t need hashes

    View Slide

  189. Numbers?

    View Slide

  190. Numbers
    tenderlove.zero function(x) { x }
    }
    tenderlove.one function(x) { f(x) }
    }
    tenderlove.two function(x) { f(f(x)) }
    }
    tenderlove.three function(x) { f(f(f(x))) }
    }
    print(tenderlove.three(function(x) { x + 1 })(0)) => 3

    View Slide

  191. Addition
    tenderlove.one function(x) { f(x) }
    }
    tenderlove.add function(f) { function(x) { a(f)(b(f)(x)) } }
    }
    tenderlove.two tenderlove.three print(tenderlove.three(function(x) { x + 1 })(0)) # => 3

    View Slide

  192. Church Encoding

    View Slide

  193. Don’t need Numbers

    View Slide

  194. Don’t need Mathematics

    View Slide

  195. Logic?

    View Slide

  196. true / false / if
    True = ->(x, y) { x }
    False = ->(x, y) { y }
    If = ->(cond, t, f) { cond.(t, f) }
    If.(True, ->() { :true }, ->() { :false }).call # => :true
    If.(False, ->() { :true }, ->() { :false }).call # => :false

    View Slide

  197. Don’t need booleans

    View Slide

  198. Don’t need conditionals

    View Slide

  199. My Signal (crap data)
    -100
    925
    1950
    2975
    4000
    Time
    2017-01-23
    15:53:51
    2017-01-23
    15:53:56
    2017-01-23
    15:54:01
    2017-01-23
    15:54:06
    2017-01-23
    15:54:11
    2017-01-23
    15:54:16
    2017-01-23
    15:54:21
    2017-01-23
    15:54:26
    2017-01-23
    15:54:31
    2017-01-23
    15:54:37
    2017-01-23
    15:54:42
    2017-01-23
    15:54:47
    2017-01-23
    15:54:52
    2017-01-23
    15:54:57
    2017-01-23
    15:55:02
    2017-01-23
    15:55:07
    2017-01-23
    15:55:12
    2017-01-23
    15:55:17
    2017-01-23
    15:55:22
    2017-01-23
    15:55:27
    2017-01-23
    15:55:32

    View Slide

  200. cons / car / cdr / each
    tenderlove.cons tenderlove.car tenderlove.cdr tenderlove.each if (!is.null(lst)) {
    element func(element)
    tenderlove.each(func, tenderlove.cdr(lst))
    }
    }
    tenderlove.each_with_index idx tenderlove.each(function(element) {
    func(idx, element)
    idx = idx + 1
    }, lst)
    }

    View Slide

  201. array indexing
    tenderlove.vec_at if(idx == 0) {
    tenderlove.car(lst)
    } else {
    tenderlove.vec_at(idx - 1, tenderlove.cdr(lst))
    }
    }

    View Slide

  202. Converting Vectors to cons
    tenderlove.c2cons foldl if(length(lst) == 0) {
    init
    } else {
    foldl(proc, proc(head(lst, 1), init), tail(lst, -1))
    }
    }
    foldl(tenderlove.cons, NULL, rev(cs))
    }

    View Slide

  203. Convolution in R
    tenderlove.conv x_list h_list indexes sapply(indexes, function(i) {
    sum(tenderlove.cons2c(tenderlove.map_with_index(function(j, h_j) {
    if (i - j < 0 || i - j > length(x) - 1) {
    0
    } else {
    h_j * tenderlove.vec_at(i - j, x_list)
    }
    }, h_list)))
    })
    }

    View Slide

  204. Feed in test data
    > data > plot(data)
    > filter > plot(filter)
    > plot(tenderlove.conv(data, filter))

    View Slide

  205. * =
    Nice.
    tenderlove

    View Slide

  206. Input Real Data
    > plot(tenderlove.conv(unlist(dat$V2), c(1)))
    Error: evaluation nested too deeply: infinite
    recursion / options(expressions=)?
    I f#[email protected]*ing hate R.
    tenderlove

    View Slide

  207. Things I don’t have time for:
    Figuring out R.

    View Slide

  208. My Signal (crap data)
    -100
    925
    1950
    2975
    4000
    Time
    2017-01-23
    15:53:51
    2017-01-23
    15:53:56
    2017-01-23
    15:54:01
    2017-01-23
    15:54:06
    2017-01-23
    15:54:11
    2017-01-23
    15:54:16
    2017-01-23
    15:54:21
    2017-01-23
    15:54:26
    2017-01-23
    15:54:31
    2017-01-23
    15:54:37
    2017-01-23
    15:54:42
    2017-01-23
    15:54:47
    2017-01-23
    15:54:52
    2017-01-23
    15:54:57
    2017-01-23
    15:55:02
    2017-01-23
    15:55:07
    2017-01-23
    15:55:12
    2017-01-23
    15:55:17
    2017-01-23
    15:55:22
    2017-01-23
    15:55:27
    2017-01-23
    15:55:32

    View Slide

  209. Something I built

    View Slide

  210. View Slide

  211. Bathroom Scale

    View Slide

  212. msp430

    View Slide

  213. Raspberry Pi + Motion Sensor

    View Slide

  214. Litter Box

    View Slide

  215. I made this
    Weight (g)
    -100
    925
    1950
    2975
    4000
    Time
    2017-01-23
    15:53:51
    2017-01-23
    15:53:56
    2017-01-23
    15:54:01
    2017-01-23
    15:54:06
    2017-01-23
    15:54:11
    2017-01-23
    15:54:16
    2017-01-23
    15:54:21
    2017-01-23
    15:54:26
    2017-01-23
    15:54:31
    2017-01-23
    15:54:37
    2017-01-23
    15:54:42
    2017-01-23
    15:54:47
    2017-01-23
    15:54:52
    2017-01-23
    15:54:57
    2017-01-23
    15:55:02
    2017-01-23
    15:55:07
    2017-01-23
    15:55:12
    2017-01-23
    15:55:17
    2017-01-23
    15:55:22
    2017-01-23
    15:55:27
    2017-01-23
    15:55:32
    Cat Enters Cat Leaves

    View Slide

  216. ~100g

    View Slide

  217. Wrap-Up

    View Slide

  218. It’s hard to make shit scale
    I told you those graphs were crap

    View Slide