Microstation To Find Line Or Arc Of Best Fit.

Question

Hi all 
 I have a problem which I was hoping someone could help with. 
 I have entered approx 40 x, y, z co-ordinates into microstation using the XYZ text tool box. 
 What I would like to do is get microstation to find either a line of best fit or an arc of best fit by selecting a series of points. Once the line/arc has been created I want to know how far away the points are from the line or arc. 
 After browsing the functionality I have struggled to come up with anything. I am currently using Microstation Select Series 2. 
 Can anyone help? 
 (I&rsquo;m a bit dense so screen shots will help a great deal. Lol) 
 Thanks

Jon Summers · Accepted Answer

Unknown said: I would like to get microstation to find a line of best fit 
 That's termed regression analysis . AFAIK MicroStation has no built-in capability for that. 
 From your other posts it looks like you might be using a civil engineer app. Doesn't that offer some form of line-fitting capability?

Lorys · Answer

try excel instead to do the regression analysis then you use the answer to imbed into cad or export the answer or get excel to give you the equation then use the tool for equations to draw it ( forgot what its called at the moment) but excel do this better.

Andrew Bell · Answer

I agree with Jon Summers. What you are talking about sounds like Regression Analysis which is an integral part of Bentley InRoads civil design software. 
 www.bentley.com/.../product-overview.htm 
 Maybe this question would be better suited to the Road and Site Design forum. 
 communities.bentley.com/.../default.aspx

Peter F · Answer

On academic level of thinking this is very easily done with parametric add on "apps" (like the evolving solver Galapagos and/or the physics solver Kangaroo) that run on top of Grasshopper (that's a Rhino "add-on"). The parametric code is called "definition" and there's numerous similar cases with yours (available for free) in the Grasshopper related Forums ((a) general discussions and (b) examples). 
 So still in academic waveband ... you could do it in Rhino and reference (live) the file(s) in Microstation etc etc etc. 
 Unfortunately none of the above work with Microstation - but there's a parametric MS companion called Generative Components (either as stand alone or add-on to MS). 
 best, Peter

Peter F · Answer

BTW: In the distant past, I've created a lot of "definitions" with the best fit theme - for a variety of reasons (this one captured interpolates bezier curves AND creates a "best-fit" arc using Galapagos). Mail me your points and the arc (and any sort of data related with anything) is a matter of seconds.

stefan_bernsdorf · Answer

Looks like a VBA job to me. 
 Regards, Stefan.

Jon Summers · Answer

Unknown said: Use the tool for equations to draw it 
 MicroStation's equation tool was introduced a long time ago, with MicroStation/J or earlier. It's awkward to use and is eclipsed by MicroStation VBA. 
 MicroStation: Plotting Curves with VBA 
 
 This article about plotting curves with MicroStation VBA illustrates how to use MicroStation as a curve-plotting tool.

Jon Summers · Answer

Unknown said: Looks like a VBA job to me &hellip; 
 Regression Analysis using VBA 
 We created a MicroStation VBA project to perform a linear best-fit regression analysis. 
 
 You can read about the VBA regression analysis project , and download a ZIP file. The ZIP file contains the complete VBA project, including source code. You can view and modify the code to suit your needs. 
 Updated 16-May-14 
 Stefan Bernsdorf kindly contributed to this VBA project. He added code to use a selection set of MicroStation elements as a data source. The code on our web site incorporates his ideas. Thanks, Stefan!

Lorys · Answer

I still think transfer your xyz coords ( you must have a table already as you said you imported to plot via xyz tools) to excel use the tools in excel to determine the regression analysis , line of best fit, standard deviation etc and solve the equation ... now you have the standard dev you now the average of the average distance 
 from the curve....you can also now redraw the curve using the equation with MicroStation's equation tool or by calculation via excel to give you the new points that lie on the curve... it helps if you draw the axes and grids in cad... as said above several times to save time use excel to do the math and stats analysis then use mstn to do the drawing part.. you can still leave your original points to show how the line fits, state the equation or y is a f(x) and the standard deviation ie + or - 
 Best solution given limited effort and limited resources every office has excel or excel like tools open office etc.. 
 and you already have Mstn CAD.. its a no brainer... look forward to a screen shot of your labelled cad curve...

Microstation To Find Line Or Arc Of Best Fit.

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