Tag Archives: programming

Wind,Temperature,Air Pressure statistics

The above graphs show statistics from SMHI, the swedish meteorological and hydrographical institute, on air pressure, temperature and wind speed.  For each categrory, (pressure,temp,wind speed) there are two graphs: the first a frequency chart, the second a Q-Q-chart, showing the … Continue reading

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Wind Speed Distribution – is it Normal…?

As a sailor, I’ve become obsessed by wind. Trying to understand its behavior has kept me busy for decades, and still, I can’t claim I fully understand wind behavior. Anyways, one of the things I’ve wondered is whether wind is … Continue reading

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Map Projections using Python & Basemap

The numerous external libraries available for Python continue impressing me, in scope, numbers and ease of use.  A couple of hours ago I googled for chartographic tools for Python, and found the Basemap-library, an add-on to Matplotlib. For whatever reason, … Continue reading

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Improving Python performance by factor of 100

I’m doing a bit of Machine Learning on my spare time. A neural network that analyzes images. Anyways, since I don’t have zillions of computing power, any decent amount of learning data takes hours and days to process thru my … Continue reading

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Machine Learning with PyBrain

Looks very impressive, a comprehensive library for machine learning using Python.

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Facial detection using OpenCV & Python on Windows7-Cygwin64

Finally! As described in my previous post, I had some struggle getting OpenCV to run at all under my Windows7 / Cygwin64 installation, but eventually I managed getting it working for C++. However, Python still refused to cooperate with OpenCV, … Continue reading

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Python image processing – object recognition

When looking for a function enabling me to do normalized cross correlation of images, for purposes of object recognition, I stumbled upon an extension to the SciPy library: SciKit-image. After a few minutes of browsing that site I was able … Continue reading

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image processing – convolution explained.

The Python code below demonstrates convolution.  First, using Scipy’s convolve() function, then by two – far from optimal, far from high performance!  – ‘invented-here’ implementations of convolve(), that I hacked in order to understand what Scipy’s convolve() actually does. The … Continue reading

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Image processing with Python, Numpy & Scipy – image convolution

I spent a few hours tonight learning the basics of image processing. In particular, I wanted to understand convolution, that is, a techique for applying various types of filters to images. I’m not going to cover all the nitty gritty … Continue reading

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Simple image processing with Python, Numpy & Matplotlib

When I saw the topmost image on the Russian riot police, I just had to do a simple image transformation, more specifically, a reflection, to produce a mirror image. Numpy’s powerful functions makes such a tranformation very simple.   import … Continue reading

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