gistfile1.rb

srand 0

WIDTH, HEIGHT = 10, 10
array = Array.new(HEIGHT){ [0]*WIDTH }

require "profile"
10000.times do
    y, x = rand(HEIGHT), rand(WIDTH)
    g = array[y][x] + [-1,+1].sample
    array[y][x] = g unless [[y-1,x],[y+1,x],[y,x-1],[y,x+1]].any?{ |y, x|
        y>=0 && y<HEIGHT && x>=0 && x<WIDTH && 1 < (array[y][x] - g).abs
    }
end

gistfile2.txt

  %   cumulative   self              self     total
 time   seconds   seconds    calls  ms/call  ms/call  name
 44.00     0.44      0.44    38175     0.01     0.03  nil#
 17.00     0.61      0.17    10000     0.02     0.04  Array#each
 12.00     0.73      0.12    20000     0.01     0.01  Kernel#rand
 11.00     0.84      0.11    10000     0.01     0.05  Enumerable#any?
  6.00     0.90      0.06        1    60.00  1000.00  Integer#times
  4.00     0.94      0.04    25500     0.00     0.00  Fixnum#abs
  4.00     0.98      0.04    10000     0.00     0.00  Array#sample
  2.00     1.00      0.02    20000     0.00     0.00  Kernel#respond_to_missing?
  0.00     1.00      0.00        1     0.00     0.00  TracePoint#enable
  0.00     1.00      0.00        1     0.00     0.00  MonitorMixin#mon_exit
  0.00     1.00      0.00        1     0.00     0.00  Mutex#unlock
  0.00     1.00      0.00        1     0.00     0.00  MonitorMixin#mon_check_owner
  0.00     1.00      0.00        1     0.00     0.00  MonitorMixin#mon_enter
  0.00     1.00      0.00        1     0.00     0.00  Mutex#lock
  0.00     1.00      0.00        3     0.00     0.00  Thread.current
  0.00     1.00      0.00        1     0.00     0.00  TracePoint#disable
  0.00     1.00      0.00        1     0.00  1000.00  #toplevel

gistfile3.txt

srand 0

WIDTH, HEIGHT = 10, 10
array = Array.new(HEIGHT){ [0]*WIDTH }

require "ruby-prof"

RubyProf.start
10000.times do
    y, x = rand(HEIGHT), rand(WIDTH)
    g = array[y][x] + [-1,+1].sample
    array[y][x] = g unless [[y-1,x],[y+1,x],[y,x-1],[y,x+1]].any?{ |y, x|
        y>=0 && y<HEIGHT && x>=0 && x<WIDTH && 1 < (array[y][x] - g).abs
    }
end
result = RubyProf.stop

printer = RubyProf::FlatPrinter.new(result)
printer.print(STDOUT)

gistfile4.txt

Thread ID: 70100140233520
Fiber ID: 70100140080880
Total: 0.109966
Sort by: self_time

 %self      total      self      wait     child     calls  name
 32.07      0.044     0.035     0.000     0.008    10000   Array#each 
 26.74      0.110     0.029     0.000     0.081        1   Integer#times 
 15.32      0.024     0.017     0.000     0.007    20000   Kernel#rand 
  7.89      0.052     0.009     0.000     0.044    10000   Enumerable#any? 
  7.66      0.008     0.008     0.000     0.000    25500   Fixnum#abs 
  6.69      0.007     0.007     0.000     0.000    20000   Kernel#respond_to_missing? 
  3.61      0.004     0.004     0.000     0.000    10000   Array#sample 
  0.03      0.110     0.000     0.000     0.110        1   Global#[No method]