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Why can't they mention "CORDIC" so that interested readers can find out the cool details about how to actually calculate "... trigonometric functions by repeate
by drfuchs 6y ago
Why can't they mention "CORDIC" so that interested readers can find out the cool details about how to actually calculate "... trigonometric functions by repeatedly rotating an initial vector until the target angle was reached..." using only fixed-point add, subtract, and shift?
- Someone 6y agoNitpick: this calculator uses only one of the core ideas of CORDIC: that one can compute sines and cosines by repeated rotation. It doesn’t use the other core idea that you can approximate any angle by successively halving each step. It doesn’t do the latter because of lack of memory to implement it in. http://files.righto.com/calculator/sinclair_scientific_simulator.html http://files.righto.com/calculator/sinclair_scientific_simul...: “How can sine and cosine be computed efficiently in a calculator that has a hard time even doing multiplication? The trick is to do repeated rotations by 0.001 radians until the desired angle is reached. […] Other calculators use algorithms such as decimal CORDIC that are much faster and more accurate, taking time proportional to the number of digits.”