From the category archives:

algorithms

Fun with none

by rohit on July 16, 2009

(If you are in a hurry, here is the fun part. A few days ago, I was working with a nullable field, which wasn’t behaving as I expected. So I started a shell, and see how nulls compare. In [1]: None In [2]: None > 10 Out[2]: False In [3]: None < 10 Out[3]: True [...]

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Generating pseudo random text with Markov chains using Python

by shabda on June 16, 2009

First the definition from Wolfram A Markov chain is collection of random variables {X_t} (where the index t runs through 0, 1, …) having the property that, given the present, the future is conditionally independent of the past. Wikipedia is a little clearer …Markov chain is a stochastic process with markov property … [Which means] [...]

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Finding keywords using Python

by lakshman on March 9, 2009

Update: keywords2.txt is Pride and Prejudice from Project Gutenberg. Attached for convenience. Finding keywords in a given snippet of text has many uses. From classifying web pages to fighting spam mails, keyword recognition is the first step in many algorithms. We here show the naive Bayesian filter to find keywords, which was popularised by Paul [...]

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Constraint programming in Python

by shabda on March 6, 2009

Imagine this, you want to solve a problem, the algorithm for which you do not know. You just know the problem. From wikipedia, Constraints differ from the common primitives of imperative programming languages in that they do not specify a step or sequence of steps to execute, but rather the properties of a solution to [...]

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