duplicates = multiple editions
A Classical Introduction to Modern Number Theory, Kenneth Ireland Michael Rosen
A Classical Introduction to Modern Number Theory, Kenneth Ireland Michael Rosen
(defn words [text] (re-seq #"[a-z]+" (.toLowerCase text))) | |
(defn train [features] | |
(reduce (fn [model f] (assoc model f (inc (get model f 1)))) {} features)) | |
(def *nwords* (train (words (slurp "big.txt")))) | |
(defn edits1 [word] | |
(let [alphabet "abcdefghijklmnopqrstuvwxyz", n (count word)] | |
(distinct (concat |
#!/usr/bin/env python | |
""" | |
Shows git branches sorted by last commit date, noting when branch has been | |
merged: | |
$ git blast | |
* master 33 minutes ago | |
david 4 days ago [M] | |
unholy-david-payments 4 days ago | |
handsontable-2 5 days ago |
;; Based on https://clojuredocs.org/clojure.core/condp#example-542692cbc026201cdc326bea | |
(defn parse-arg [s] | |
(condp (comp next re-matches) s | |
#"([+-])(\w+)" :>> (fn [[f k]] [(keyword k) (= f "+")]) | |
#"(\w+)=(\w+)" :>> (fn [[k v]] [(keyword k) v]) | |
(throw (IllegalArgumentException. s)))) | |
(parse-arg "+foo") ;=> [:foo true] | |
(parse-arg "-foo") ;=> [:foo false] |
Latency Comparison Numbers | |
-------------------------- | |
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 | |
Send 1K bytes over 1 Gbps network 10,000 ns 0.01 ms | |
Read 4K randomly from SSD* 150,000 ns 0.15 ms |
As configured in my dotfiles.
start new:
tmux
start new with session name:
A friend asked me for a few pointers to interesting, mostly recent papers on data warehousing and "big data" database systems, and I figured I'd share the list. This is biased and rather incomplete but maybe of interest to someone. While many are obvious choices, I think there are a few underappreciated gems.
###Dataflow/Stream Processing Engines:
Dryad--general-purpose distributed parallel dataflow engine
http://research.microsoft.com/en-us/projects/dryad/eurosys07.pdf
Google Dremel--columnar storage for fast queries (c.f. Impala)
http://static.googleusercontent.com/external_content/untrusted_dlcp/research.google.com/en/us/pubs/archive/36632.pdf