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Author Topic: Precise MATH Instructions  (Read 23005 times)

Bolt

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Re: Precise MATH Instructions
« Reply #15 on: July 30, 2021, 07:57:04 PM »
Quote from: BobO on July 30, 2021, 05:27:19 PM
Quote from: Bolt on July 30, 2021, 04:03:53 PM
Are you sure you can't just add a little code to allow us to cast R's to a R:DP? :P

Yeah...um. Sorry.

I actually fought with similar issues while developing the motion functions. Single precision wasn't accurate enough in a few of the axis calculations so I had to selectively add double. It was a little tricky getting the balance of accuracy and performance.

I know, you should come out with a MATH co-processor POM!
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franji1

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Re: Precise MATH Instructions
« Reply #16 on: July 31, 2021, 08:35:00 AM »
It appears that on the first couple of angles you are multiplying R11+R12 by 2 but also dividing by 2?  Definitely losing 1 bit of significance there.
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Bolt

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Re: Precise MATH Instructions
« Reply #17 on: July 31, 2021, 05:12:00 PM »
Quote from: franji1 on July 31, 2021, 08:35:00 AM
It appears that on the first couple of angles you are multiplying R11+R12 by 2 but also dividing by 2?  Definitely losing 1 bit of significance there.

Yep, tunnel vision.  The formula calls for twice the mean angle, which would be the same as summing the two angles.  But, no change in resolution for me.  Either way, I'm still many bits away from having the resolution needed for this prospective project.  Thanks!
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