John D. Cook
• John
A couple years ago I wrote about how to compute the inverse of factorial. I used that code in writing the previous post because the post required solving the equation ⌊log2(n!)⌋ = b given b. That is, given a number of bits b, find the smallest value of n such that n! > 2b. What the […]
The post Inverse factorial improved first appeared on John D. Cook.
Simone Salis
• Simone Salis
How a trip in 2012 transformed my relationship with photography—from staged performances to capturing genuine moments that matter, for engagement rather than validation.
John D. Cook
• John
The previous post looked at the idea of storing a cryptographic key in the order of a deck of cards. A deck of 52 cards can store 225 bits of data because ⌊log2(52!)⌋ = 225. Here ⌊x⌋ is x rounded down to the nearest integer. If we want to store bigger keys, we’re going to need […]
The post Cryptographic Keys and Decks of Cards first appeared on John D. Cook.
Andrew Nesbitt
• Andrew Nesbitt
Two versions of lodash walk into a tree
Terence Eden’s Blog
• @edent
For several years, Google's product help forums have been littered with people trying to download a .ics event from their email, only to receive the error "Unable to launch event" when trying to add it to Google Calendar. It doesn't happen with all iCal attachments, only some. Here's how to fix it. I checked dozens of broken iCalendar invites using this iCal validator and they all had the same …
The Silicon Underground
• Dave Farquhar
On June 29, 1993, IBM released the first energy star computer, the IBM PS/2 E. The “E” stood for energy. But while it was undeniably more efficient than other desktop PCs, arguably it was a PS/2 in name only. To
The post IBM PS/2 E: The first Energy Star computer appeared first on The Silicon Underground.
Pluralistic: Daily links from Cory Doctorow
• Cory Doctorow
John D. Cook
• John
The latest issue of Paged Out! has an article by Stephen Hewitt “An off-line backup of your cryptographic key using playing cards.” The idea is to use a deck of 52 to store a 128-bit cryptographic key. To erase the key, shuffle the deck. Hewitt gives his algorithm for embedding a key, one that can […]
The post Hiding data in permutations first appeared on John D. Cook.
The Old New Thing
• Raymond Chen
Exception-safety, the invisible bug.
The post Making an agile version of a Windows Runtime delegate in C++/WinRT, part 6 appeared first on The Old New Thing.
Tedium: The Dull Side of the Internet.
• Ernie Smith
My brain-breaking trick for weaning off of Facebook involved creating a fake URL for Google News. Blame the home row.
John D. Cook
• John
My post from yesterday on permutation roots ends with a Mathematica code for finding the probability that a permutation of n elements has a kth root. This is done by finding the coefficient of xn in the generating function I wanted to say more about this, and look at implementing the same code in SymPy. […]
The post Counting permutations with roots first appeared on John D. Cook.
John D. Cook
• John
It’s well known that you can convert the base 16 (hex) representation of an integer to the base 2 (binary) representation by simply converting each digit from hex to binary. For example, CAFEhex = 1100 1010 1111 1110two I imagine it’s less well known that you can do the same thing with floating point numbers. […]
The post Printing floating point numbers in binary first appeared on John D. Cook.
Marcus on AI
• Gary Marcus
Nvidia is falling. The mood has changed.
The Silicon Underground
• Dave Farquhar
I’ve talked a lot about the advantages and disadvantages of old milestone operating systems. But what were the advantages and disadvantages of Windows NT 3.1, first released July 27, 1993? That’s a fair question, and there are valid reasons it
The post Advantages and disadvantages of Windows NT 3.1 appeared first on The Silicon Underground.
