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Upgrading Ubuntu to 11.10
I run various versions of Ubuntu within VMware. Every single time I let it do a full upgrade to a new version it fails. This time an upgrade from 11.04 to 11.10 failed to reboot. Here’s the problem and...
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Weather Prediction Error
I wrote a Python script to download the 1 through 5 day predictions for the weather in the top 50 American cities from the Weather Underground. I’ve got almost 2 years of data now. Here are the RMSE...
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PyPy is fast
I wrote a small Python program that maintains a heap. It took 20 minutes to process a very large data file with Python 2.7. On a whim I tried PyPy. It finished the task in 1 minute. That’s 20X faster...
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You’re throwing money away!
I am for the first time seriously considering making a bid on a home. Coincidentally, two seemingly intelligent women chattering next to me at lunch today agreed that when renting “you are throwing...
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Ubuntu Software Center UI issues
I’ve loaded Precise into VMware (2GB, 2 cores). In 30 minutes I’ve run across so many UI idiosyncrasies in Software Center that I can’t remember them all. Here’s a short list: When I installed git, it...
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Ubuntu is too much work
I’m returning my laptop’s SSD for a replacement drive. In the meantime, I loaded Ubuntu Precise on my Sony Z. I usually run Windows w/ Linux in a VM. The installation actually went just fine. It looked...
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Microsoft Surface
On the day the iPad was announced my first thought was to stick a thin keyboard on the case. Two years later Microsoft has implemented the idea exactly as I had imagined it on their new Surface tablet....
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Bloom Filter in C#
Here’s a simple implementation of a Bloom Filter. public class BloomFilter { HashAlgorithm hash; int m, n, k; BitArray table; public BloomFilter(HashAlgorithm h, int size, float falsePositiveRate) {...
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Combinations
Python code to generate k-combinations from N numbers. Included is a recursive and an iterative version. It’s easy. def choose_rec(n,k): a = range(k) choose_rec(0,n,k,0,a) def...
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I Use This
At usesthis.com they interview a bunch of people to ask about their current computer setup and their dream setup. Most of them are using aged machines, ultraportables (Mac Air is popular), and...
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First time Mac User
The defining characteristic of the Macs I used in the 80s is they always lost my homework. Therefore, I’ve always owned a Windows PC for personal use and used Unix for development. But this year I...
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Apple’s Continuity
The people at Apple read my old blog post and answered with Continuity. This is a far better approach than Microsoft’s Surface Pro, which attempts to physically merge 2 devices into 1. Apple will let...
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My Next Language
I have a decent background in programming languages. In a professional context (i.e., for real money) I’ve used C#, Scheme (my favorite), Lisp, and C. For projects I’ve also used Java, C++, and Python....
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Rerunning an old benchmark
In 2011, Robert Hundt published this paper testing the performance of several languages on a loop detection task typically found in compilers. The code is available here. Go had to tweaked a bit. I ran...
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LINQ Unfold Operator
In Scheme’s SRFI-1 List library there’s a fold and unfold function. The fold is similar to the Aggregate operator in LINQ. However, there doesn’t appear to be anything like an unfold in LINQ. What is...
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Probabilistic Reactive Extensions: ProbablyDistinct
Reactive Extensions has an operator called Distinct. As data streams through, it filters out any items it has already seen before, allowing only unique items to pass to OnNext. The problem is Distinct...
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Simple Dropbox client w/ Reactive Extensions
Reactive Extensions is ideally suited to the task of monitoring a directory for changes. While the events from FileSystemWatcher are ok, it isn’t efficient. The goal is to send as little data as...
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Storm w/ Reactive Extensions and Dataflow
The Apache Storm project is a distributed dataflow framework. It’s used by Twitter to process a continuous stream of tweets through a network of machines. Microsoft’s TPL Dataflow library is similar,...
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Build an interpeter in .NET
A long while ago I noted one could build an efficient language interpreter if the runtime could inline operations more aggressively. .NET has long had an attribute called MethodImplAttribute that gives...
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3-way merge of PowerPoint with git
This doesn’t work for some reason, but I’ll make a note and look at it later. On the Mac’s Script Editor, the dictionary for MS PowerPoint 2011 says it has a method called mergeWithBaseline. That...
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