How to draw lines or arcs among average points position

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glendon
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How to draw lines or arcs among average points position

Post by glendon » Fri Jan 29, 2010 12:46 pm

it is very common that a spot is surveyed 2 or more times. their average positions need to be used to draw lines or arcs, I didn't find a quick way to do that, except using mid of 2 pts, arc center of 3 pts, no way to deal with 3 more pts.

thanks

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Brian Sloman
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Re: How to draw lines or arcs among average points position

Post by Brian Sloman » Fri Jan 29, 2010 2:12 pm

Hi, Look into the LSC command (MsCogo | Best Fit a Curve). It's a very in-depth command based on a least-squares computation and it has a lot of options, so i definately recommend checking out the help file and training movie on it, in the help file search for "Best Fit a Curve" to quickly find it.
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MicroSurvey Software Inc.

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Jason Poitras
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Re: How to draw lines or arcs among average points position

Post by Jason Poitras » Fri Jan 29, 2010 2:20 pm

As Brian mentioned you can use some of best fit routine to fit a line or arc through existing points. You also have the options of having MicroSurvey compute a new average position of a selected group of points. The command to do this is called "Multiple Point List" or MEDITP at the command line.

This routine allows you to check the residuals between points, and if needed compute a new averaged point, it is quite powerful.
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glendon
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Re: How to draw lines or arcs among average points position

Post by glendon » Fri Jan 29, 2010 2:54 pm

Thank you both, but that is not the solution I want.

e.g. I want to draw lines among stations A, B and C. A is surveyed and digital collected 4 times(2 by total station double center, and 2 by GPS), so is B and C. Assume B is the supposed joint point, best fits A and B, so does B and C, but the two lines do not join at the same point. it is worse when 2 more lines joins at the same spot.

I think a cogo function may be developed, start piont can be selected for "average of points".

Thanks again

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