wwarriner

wwarriner

List of Environment Variables in Windows Operating System

Windows XP Environment Variables

Environment Variable	Path
%ALLUSERSPROFILE%	C:\Documents and Settings\All Users
%APPDATA%	C:\Documents and Settings{username}\Application Data
%COMMONPROGRAMFILES%	C:\Program Files\Common Files
%COMMONPROGRAMFILES(x86)%	C:\Program Files (x86)\Common Files

wwarriner

The properties function of MATLAB dynamicprops handle classes is not returned in sorted order, and isn't even self-consistent. Multiple class initializations followed by clear classes can return different orders each time. Since R2018b (and maybe earlier) one can do the following to return properties in sorted order.

Add public overrides for properties and fieldnames like below. Technically properties() isn't a method of handle dynamicprops, but this should still work because methods are called before built-ins (https://www.mathworks.com/help/matlab/matlab_prog/function-precedence-order.html).

function value = properties( obj )
    if nargout == 0
        disp( builtin( "properties", obj ) );
    else
        value = sort( builtin( "properties", obj ) );

wwarriner

# Enable Powerlevel10k instant prompt. Should stay close to the top of ~/.zshrc.
# Initialization code that may require console input (password prompts, [y/n]
# confirmations, etc.) must go above this block; everything else may go below.
if [[ -r "${XDG_CACHE_HOME:-$HOME/.cache}/p10k-instant-prompt-${(%):-%n}.zsh" ]]; then
  source "${XDG_CACHE_HOME:-$HOME/.cache}/p10k-instant-prompt-${(%):-%n}.zsh"
fi

# Lines configured by zsh-newuser-install
HISTFILE=~/.histfile
HISTSIZE=1000

wwarriner

Table of Contents

• set -e, -u, -x, -o pipefail
• set -e
• set -x
• set -u
• set -o pipefail
• Setting IFS
• Original Reference

set -e, -u, -x, -o pipefail

wwarriner

Hex Codes for Nature letter "Points of view: Color blindness"

Hex codes for https://www.nature.com/articles/nmeth.1618.

Name	R	G	B	HEX
Black	0	0	0	#000000
Orange	230	159	0	#E69F00
Sky Blue	86	180	233	#56B4E9
Bluish Green	0	158	115	#009E73

wwarriner

name: sqlalchemy
channels:
  - conda-forge
dependencies:
  - pandas=2.0.2
  - pip=22.3.1
  - python=3.10.9
  - sqlalchemy=1.4.39
  - pip:
      - psychopg2-binary==2.9.6

wwarriner

# History extensions
shopt -s histappend
export HISTCONTROL=ignoredups:erasedups  # no duplicate entries
export HISTSIZE=1000
export HISTFILESIZE=100000
export HISTTIMEFORMAT='%F %T '           # Include history time stamps

# Save and reload the history after each command finishes
export PROMPT_COMMAND="history -a; $PROMPT_COMMAND"

wwarriner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

wwarriner

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs