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@karpathy
karpathy / min-char-rnn.py
Last active September 28, 2025 12:09
Minimal character-level language model with a Vanilla Recurrent Neural Network, in Python/numpy
"""
Minimal character-level Vanilla RNN model. Written by Andrej Karpathy (@karpathy)
BSD License
"""
import numpy as np
# data I/O
data = open('input.txt', 'r').read() # should be simple plain text file
chars = list(set(data))
data_size, vocab_size = len(data), len(chars)

Reading SBT Credentials from OS X Keychain

In the following, replace the REPO_NAME value with the natural-language name of your repository, replace REPOSITORY with the domain name (e.g. repo1.maven.org) and replace USERNAME with your repository user.

credentials += {
  val Password = """.*password: "([^"]+)".*""".r
  var lines: String = ""
  val logger = new ProcessLogger {
 def info(s: => String) = {}
@kelvinn
kelvinn / cmd.sh
Created July 24, 2014 02:55
Example of using Apache Bench (ab) to POST JSON to an API
# post_loc.txt contains the json you want to post
# -p means to POST it
# -H adds an Auth header (could be Basic or Token)
# -T sets the Content-Type
# -c is concurrent clients
# -n is the number of requests to run in the test
ab -p post_loc.txt -T application/json -H 'Authorization: Token abcd1234' -c 10 -n 2000 http://example.com/api/v1/locations/
@jboner
jboner / latency.txt
Last active September 30, 2025 00:11
Latency Numbers Every Programmer Should Know
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