# Monthly Archives: January 2017

## Anamorphosis and symmetries

As proposed by Farris in “Creating Symmetry” we can use anamorphosis to make images of any symmetry from some other input image. Here I briefly discuss how I am doing it and what you will find in my next program. Each … Continue reading

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## Approximating the logarithm function

I still want fast approximations of the logarithm and the inverse tangent function for my work. I don’t know if they are really needed, but they are nice pillow problems to keep you from ruminating those stupid things happening now. If  x is … Continue reading

## Approximating the exponential function

The garden has frozen over and I have caught a cold. It is hard to do difficult work. Thus I continue to find fast approximations of transcendental functions. This is more fun than solving crossword puzzles. The exponential function is not … Continue reading

## Fast approximations of the sine and cosine functions

I made up the web-page http://bookofgames.ch/fastSin.html to check out the different approximations for sine and cosine functions. Load it and make your own tests. You can use the “save”-function of your browser to download the code, change and use it for … Continue reading

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## Accelerating functions with tables

To get fast function evaluations we use tables of function values f(x_i) at equidistant points x_i=i*Δ. Taking for any x the nearest point x_i with |x_i-x|<Δ we can approximate f(x)≅f(x_i). This is the fastest and least accurate approximation. What is … Continue reading