 | | basic trigonometric functions on the handyboard..
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Hi. We've been trying to build an algorithm which will allow our HB to travel between given points. We need to use the inverse cosine function (cos^-1), how can we do that? Is there a math library which contains this and other trig functions? (...) (25 years ago, 9-Mar-99, to lugnet.robotics.handyboard)
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| | Re: basic trigonometric functions on the handyboard..
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Hi, The taylor for cos^-1 goes: cos^-1(x) = Pi/2- (x + 1/2*x^3/3 + 1/2*3/4*x^5/5 + 1/2*3/4*5/6*x^7/7 ...) (which in fact is simply Pi/2 - sin^-1) The results are very good for small x. For x close to 1 you need many many elements of that series to (...) (25 years ago, 9-Mar-99, to lugnet.robotics.handyboard)
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| | Re: basic trigonometric functions on the handyboard..
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A Taylor series isn't the way to go: they converge far too slowly. Here is a polynomial fit to arccos(x): arccos(x) ~ = 1.5708 - 1.0927 x + 4.358 x^3 - 0.8340 x^5 It differs from the exact value of arccos(x) by no more that 0.08 radians (4.6 (...) (25 years ago, 9-Mar-99, to lugnet.robotics.handyboard)
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| | Re: basic trigonometric functions on the handyboard..
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Dear Berg, You can perhaps express cos^-1 in the forms of a Taylor series and use that series for finding the approximate value. I have however not tried it. There is no math function for inverse cosine.Refer to handy board manual available (...) (25 years ago, 9-Mar-99, to lugnet.robotics.handyboard)
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