Programming

Numpy and scipy in Snow Leopard

Chris H. — Wed, 02 Sep 2009 21:51:42 +0000

I just upgraded to Snow Leopard and found that using the Scipy Superpack from macinscience.com doesn't yet work. I got it working, and document the process here. You might be better off waiting for the latest Scipy Superpack, but I needed to get back to work so I wanted things working today.

Python 2.6.2 breaks cron jobs in OS X

Chris H. — Mon, 04 May 2009 06:59:04 +0000

I recently decided to install Python 2.6.2 in OS X Leopard, which ships with Python 2.5.1. I downloaded the latest Python 2.6 from python.org, and it installed without a problem. I ran a few of my scripts to test it out and still didn't have any issues. However, the next day I noticed that all of my python-based cron jobs had all failed with similar errors:

Traceback (most recent call last): 
  File "/Users/chlady/Documents/git/script.py", line 3, in import simplejson as json 
ImportError: No module named simplejson

Installing numpy and scipy on OS X Leopard

Chris H. — Thu, 02 Apr 2009 18:45:04 +0000

Every time I try building scipy on OS X run into some frustrating problems. In an attempt to prevent this from happening again I'm documenting the process here.

Prime Furniture

Chris H. — Sun, 04 Jan 2009 22:32:44 +0000

This Enigma was published in New Scientist on December 13, 2008. The original author is Adrian Somerfield.

Original Question

SOME three-digit primes are formed from a one-digit prime followed by a two-digit prime, others from a two-digit prime followed by a one-digit prime, and some can be in both classes. I recently bought three pieces of furniture, and each cost a different sum which was one of the last-mentioned type of prime (in euros), but the total I paid was not a prime. In ascending order, what were the prices of my pieces of furniture?

Rewritten

Find three three-digit primes whose sum is not prime, and where the first and last digits are primes, and the first two and last two digits form primes.