Monday, July 27, 2009

Debugging Note
On Friday, I discovered Python's weirdness with mutable default arguments. Default arguments are given space in memory when their function is defined, not when it is called- so Python sets them once and never checks up on them again. Usually, that's fine... but when the default is mutable and its value is changed, it retains the changed value until such time as it's updated again. It acts like a secret global variable, and it's a very, very special thing to debug.

Comparison of Filter Functions
I'm working on a preliminary/exploratory assessment of the rankings that are produced by filter functions. Since the metadata standards tend to be pretty long, I'm looking at clusters of related terms that have direct crosswalks between FGDC and EML. A better ranking will be characterized by the appearance of cluster members (a) close together and (b) near the top of the list.

Results to follow....

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