MapCleanup overlapping PL (vertices in other order) NOT duplicate PL

[luc.vanlinden]

Hi

Seems MAP2014 MapClenaup does NOT detect overlapping closed polylines digitised with vertices in different order as being duplicate.

All properties are the same, "spatially" they are equal, they even have equal number of vertices, and the vertices are equal, only the order in which they are digitised is different, meaning the startpoint/1st vertex is different.

Funny, when the start point is equal, but the direction is reversed then they are seen as duplicate.

How can these be detected if MapCleanup fails do do so?

Anyone else has experienced this?

tx

Luc Van Linden

[Alfred.NESWADBA]

Hi,

just to make sure that there are not more than your circumstances necessary to get that produced ... can you upload a drawing with 2 polylines so we can try to reproduce that?

- alfred -

[luc.vanlinden]

Hi Alfred

Please find attached the sample example drawing.

2 situations:

left: 2 "duplicate" polylines different orientation with same start vertex.

MapCleanup - select manual (2 left pl) - delete duplicates - duplicates detetected by mapcleanup

right: 2  "duplicate" polylines different start vertex

MapCleanup - select manual (2 right pl) - delete duplicates - duplicates NOT detetected by mapcleanup

(all digitised with object snap; all on layer 0)

tx for looking into this

Luc

[Alfred.NESWADBA]

Hi,

I used now Map 3D 2015 SP3 64bit.

I opened your drawing and used my default cleanup-set (find attached file) and the result was ok, only one polyline where 2 existed before.

Does that work for you too or not (with my DPF)?

- alfred -

[luc.vanlinden]

Alfred

Not sure you have attatched something (dfp)?

On Map2014 SP1 the situation on the right remains the same: 0 errors were detected by Drawing Cleanup.

tx

Luc

[Alfred.NESWADBA]

Hi,

I have attached it within the ZIP, just had to update the message 😉

- alfred -

[luc.vanlinden]

Alfred

Thanks for your effort and help, much appreciated, however, your approach (DFP) is breaking everything up (you have all crossing, breaking, stuf in there).

With other words a brute force cleanup, which is not helpfull at all in our case. This works in this simplified case to demonstrated the strange and to my opinion inconsistent approach of the map cleanup tool.

That was not my question.

The question is clearly:

Should  2 polylines, which are spatially equal, which have the same number of vertices, which share the same vertices, however shared those vertices in another sequence  (in this case closed polylines with starting vertex being different), be considered as "duplicate" withing the MAPCLEANUP tool?

To my personal opinion YES, however (at least on my MAP2014) MapCLEANUP seems to be saying NOT duplicate

Funny enough, when 2 polylines start at the same vertex, sharing the same vertices but have complete different directions MAPCleanup says Yes duplicates

tx (again Alfred)

Luc

[Alfred.NESWADBA]

Hi,

well, using only cleanin goption duplicate objects with Map 3D 2015 does the same you describe and so what I see is it recognizes the objects as same as start and endpoint are the same like used in GIS-islands. The polylines with different start (and there is does not depend if they have the same or not the same direction) are not recognized as duplicates.

You can see the difference in your original drawing also when running command _OVERKILL ... there you see the issue on detecting "same objects".

I understand your wish to know the theory behind that, but do you have a short description whatfor you need cleaning only duplicates without using the other cleaning methods? I can't assume why I should avoid the other cleaning methods, neither for a network-topology nor for a polygonal topology. Maybe if we know the background of what's your workflow we find other options to do that?

- alfred -

[luc.vanlinden]

Hi Alfred

Use case is plain simple.

We got an asbuilt drawing with a lot of content, some of which contains duplicate information, and apparently with some polylines as described earlier being spatially equal (1 polyline spatially equal to the other).

We want to remove the duplicate entities.

At the same time we do not want to "explode" (brute force cleaning) as we need to retain the properties and characteristics (in this case, being closed polylines).

Cleanup is part of MAP, hence to my personal opinion, we can expect from MAP Cleanup to detect those duplicates.

tx

Luc

[Alfred.NESWADBA]

Hi,

thank you for your feedback and description of your workflow!

>> Cleanup is part of MAP, hence to my personal opinion, we can expect from MAP Cleanup to detect those duplicates.

Well, I would place that feedback to that site: >>>Products Feedback<<<

But to be honest, it's hard to say "duplicate" if polylines have different start-/enddpoints, are they equal or not, but as different directions (which might be flow directions) are seen as equal it might recognize the different points as well, I understand that.

You might run a tool that reorders the closed polylines (all clockwise) and all with the same start-vertex (lowest one, if more than one vertex have the same y-value then the leftmost one of them) ... then you find them and can clean them. But I don't know a option without such a tool now, sorry.

- alfred -