Category Archives: Math

Taking the Gopher for a spin

As originally shared on Google+, and as a follow up of the previous post covering OpenGL on Go QML, a new screencast was published to demonstrate the latest features introduced around OpenGL support in Go QML: Refrences: Go QML project … Continue reading

Posted in Architecture, Design, Go, Math, Project | 3 Comments

IEEE-754 brain teaser

Here is a small programming brain teaser for the weekend: Assume uf is an unsigned integer with 64 bits that holds the IEEE-754 representation for a binary floating point number of that size. The questions are:

Posted in C/C++, Erlang, Go, Haskell, Java, Math, Perl, Puzzle, Python, Ruby, Snippet | 7 Comments

strepr v1 (draft2)

Note: This is a candidate version of the specification. This note will be removed once v1 is closed, and any changes will be described at the end. Please get in touch if you’re implementing it. Contents Introduction Supported values Representation … Continue reading

Posted in Architecture, Article, C/C++, Cloud, Design, Erlang, Go, Haskell, Java, Lua, Math, MongoDB, Python, Ruby, Security | 14 Comments

Baby feeding statistics with R

Our son Ot├ívio was born recently. Right in the first few days, we decided to keep tight control on the feeding times for a while, as it is an intense routine pretty unlike anything else, and obviously critical for the … Continue reading

Posted in Article, Math, Mobile, R, Snippet | 1 Comment

Wiki + Spreadsheet

The underlying concept is very simple: spreadsheets are a way to organize text, numbers and formulas into what might be seen as a natively numeric environment: a matrix. So what would happen if we loosed some of the bolts of … Continue reading

Posted in Math, Project, Python | 5 Comments

Hey, nice float!

python-nicefloat is a Python module implementing an algorithm based on the paper “Printing Floating-Point Numbers Quickly and Accurately”, by Robert G. Burger and R. Kent Dybvig. The implemented algorithm will find the shortest, correctly rounded output string representing a decimal … Continue reading

Posted in Math, Project, Python | 4 Comments

Problem of the Week at University of Massachusetts

University of Massachusetts has a very nice Problem of the Week service where they post a new math related problem every monday. At that time they report the percentage of people that correctly answered the question as well. To submit … Continue reading

Posted in Math, Puzzle, Python | Leave a comment

All combinations of N elements

Here’s a snippet to compute all combinations of N elements over K positions.

Posted in Math, Python, Snippet | 3 Comments

Permutations of all subsets

Another snippet to compute the permutations of all subsets.

Posted in Math, Python, Snippet | 3 Comments

Permutations and derangements

Two snippets to compute permuatations and derangements in Python.

Posted in Math, Python, Snippet | 4 Comments