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Tim Hoolihan thoolihan

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@floer32
floer32 / matrix_multiplication_refresher.md
Last active April 13, 2022 11:59
Matrix multiplication refresher: develop your intuition for matrix multiplication! (Or, "matrix multiplication for dummies")

A refresher on matrix multiplication. Because your math classes were years ago. Here's the order I recommend:

  1. TED-Ed video — How to organize, add and multiply matrices - Bill Shillito (only 5 minutes)
  2. betterexplained.com — "An Intuitive Guide to Linear Algebra" by Kalid Azad
  3. mathinsight.org: "Matrices and linear transformations"
  4. Read some of the answers on math.stackexchange.com. You've been studying the general definition of matrix multiplication. You may wonder: "Are there other ways to define the product of two matrices?" These resources will answer, yes, there are other ways, but also explain why this general definition is the standard way.
  5. [What is the intuitive way of thinking about multiplication of m
@bishboria
bishboria / springer-free-maths-books.md
Last active March 22, 2024 11:19
Springer made a bunch of books available for free, these were the direct links
@cobyism
cobyism / osx-install-media.md
Last active March 11, 2023 00:42
Command to create installable OS X USB drive.

Creating a bootable macOS USB installer

  • First, plug in an 8GB (or bigger) USB drive, and use Disk Utility to erase it
  • If you use the default settings, you should wind up with a blank drive at /Volumes/Untitled.

With that volume in place, and with the macOS installer sitting in /Applications/Install\ macOS\ [VERSION].app, run the following command in your terminal to create a bootable install media (for Sierra):

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ macOS\ Sierra.app --nointeraction
@akiatoji
akiatoji / gist:3044056
Created July 3, 2012 23:06
Nginx + Passenger 3 + RVM for Rack app on OS X using homebrew only

Most examples I found tell you to run rvmsudo or passenger-install-nginx-module. I ran into problems with these because:

  1. rvmsudo leaves root owned directories and files under rvm passenger gem directory. This will give you seemingly odd errors later when you try to remove/upgrade passenger gem, or try to use homebrew to install passenger.

  2. There's no good place to put nginx using passenger-install-nginx-module. Putting it under /usr/local means you have to remember it's there amongst homebrew files. Anywhere else, you still have to remember you put it there. We'd rather manage nginx install via homebrew.

So to install everything with homebrew, this is what it took:

gem install passenger