Messages in this thread | | | Date | Mon, 31 May 2004 13:44:40 +0800 (WST) | From | Ian Kent <> | Subject | Re: How to use floating point in a module? |
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On Sun, 30 May 2004 ndiamond@despammed.com wrote:
> > Yes, if we use a real-time Linux and make a daemon cooperate very closely > with the driver. > > >Maybe you could use lookup tables instead of doing floating point > >arithmetic. > > You might be right, if the device can only be controlled to position itself > in say 1,000 different ways, then we could have lookup tables for 1,000 > different intervals of (emulations of) floating-point numbers, that yield > 1,000 different values of sin. Another table for cos, another for log10, > etc. But I'd still have to write my own emulations for binary operators > such as +, /, etc., since a 1,000*1,000 lookup table would be too big.
Why not scaled longs (or bigger), scalled to number of significant digits. The Taylor series for the trig functions might be a painfull.
Ian
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