| #! /usr/local/bin/ruby | |
| #********************************************* | |
| # 台形則による定積分 | |
| #********************************************* | |
| class DefiniteIntegralTrapzoid | |
| # 積分区間分割数 | |
| M = 100 | |
| def initialize | |
| # 被積分関数 |
| 1) Setup Server on Vultr | |
| Select “create New Server(e.g. 123.123.123.123)”, select “Ubuntu 14.04 LTS” | |
| Once your server has been created, wait for installation to complete. | |
| SSH into your Server as root and run the following commands: | |
| # login server by SSH | |
| ssh [email protected] | |
| # Updating apt-get | |
| sudo apt-get update # Fetches the list of available updates | |
| sudo apt-get upgrade # Strictly upgrades the current packages | |
| sudo apt-get dist-upgrade # Installs updates (new ones) |
| # NOTE: Gender is something these countries use to calculate the serial/individual number(making them even or odd) | |
| # It is not taken into consideration in this snippet but the generated numbers are still valid | |
| require 'date' | |
| age = 21 # Whatever you want it to be | |
| # Randomize month and day equal to, or lower, than the current month | |
| # to make sure the generated birth month and day has occurred in <current_year> | |
| t = Time.new | |
| year = t.year - age |
| # Install Arch Linux with full encrypted btrfs subvolume inside luks | |
| # Hardware: BIOS system, Intel GPU, Nvidia Optimus, Toshiba SSD, Wifi | |
| # Please adjust for your needs. | |
| # filename: install-arch-linux-on-btrfs-subvolume-inside-luks.txt | |
| # The official guide: https://wiki.archlinux.org/index.php/Installation_Guide | |
| # Download the archiso image from https://www.archlinux.org/download/ | |
| # Copy to a usb-drive | |
| dd bs=4M if=archlinux.iso of=/dev/sdx status=progress oflag=sync # on linux |
| #!/usr/bin/env ruby | |
| # encoding: utf-8 | |
| require 'memory_profiler' | |
| gem 'redis', ENV['RVERSION'] | |
| require 'redis' | |
| puts Process.pid | |
| puts Redis::VERSION |
When developing a program in Ruby, you may sometimes encounter a memory leak. For a while now, Ruby has a facility to gather information about what objects are laying around: ObjectSpace.
There are several approaches one can take to debug a leak. This discusses a time-based approach, where a full memory dump is generated every, say, 5 minutes, during a time that the memory leak is showing up. Afterwards, one can look at all the objects, and find out which ones are staying around, causing the
| class MyJob < ActiveJob::Base | |
| queue_as :urgent | |
| rescue_from(NoResultsError) do | |
| retry_job wait: 5.minutes, queue: :default | |
| end | |
| def perform(*args) | |
| MyService.call(*args) | |
| end |
My firends said along with sharing all these tools all the time, maintain a list. So, they don't have to search in old chats. :/ I will populate it slowly with time.
IMPORTANT❗ List is not endorsments. If you use any of these, you are on your own.
| integral :: (Fractional a, Ord a) => (a -> a) -> Integer -> a -> a -> a | |
| integral f p a b | |
| | a==b = 0 | |
| | otherwise = total 0 a | |
| where dx = (b-a)/fromInteger p | |
| total t x | x2>b = t | |
| | otherwise = total (t+(dx*(f x+(4*f ((x+x2)/2))+f x2)/6)) x2 | |
| where x2 = x+dx |
| # D subset |R Domain over which we integrate - sample D = [1,10] | |
| D = (1..10).to_a | |
| # f:|R->|R function - sample x |-> f(x) := x^2 | |
| f = lambda {|x| x*x} | |
| # summation of function values over our domain | |
| summator = lambda {|function, domain| domain.inject(0){|x,y| x += function.call(y)} } | |
| # Integrations Driver (for real valued 1d functions only) - assumption: integration steps equidistant |
