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6,300 post(s)
#05-Sep-18 08:49

I can't find a way to delete a part of a line, i.e. to split branches and delete a branch in Mfd 9. Is it just me?


5,359 post(s)
#05-Sep-18 09:24

If I understand the task, yes. :-)

Suppose you have a line with multiple branches and you want to delete one of those branches. There are two ways to do that. Here is what I did:

1. Shift-Alt-click the line to enable it for editing, opening the Contents - Record panel to the Coordinates tab. In the Coordinates tab list, select the coordinates for the branch to be deleted. Press the Delete button and then press Update Record. Done.


2. Select the target line. Use the Decompose to Branches transform with the "Restrict to selection" box checked to decompose that line into constituent branches. Select and delete the unwanted branch. Merge the remaining separate branches back into one line, if desired.

I prefer 1. above.


6,300 post(s)
#05-Sep-18 15:47

Both methods require a line composed of exactly the branches I want to manipulate.

My basic problem is to split one existing branch into three parts and delete the one in the middle.

1. I could

  • Create an area covering unwanted parts
  • create a query and use function GeomClip() with this object
  • delete the area
  • delete the query

2. Or I could manually

  • decompose to segments
  • open the resulting component
  • delete unwanted segments
  • merge the rest
  • open the resulting component
  • edit all style definitions in [mfd_meta] of the original component to refer to the last result
  • delete all intermediate components
  • look at all maps and check if they contain the original component
  • insert the result component and delete the original
  • finally delete the original component
  • and forgot to check other map-files that might link to this one

and restart with the next line that needs editing ...



5,359 post(s)
#05-Sep-18 18:58

OK. It sounds like you want to start with a continuous line that is one branch, that is, just an ordinary line that is not a branched object. You then want to delete part of the middle of the line, so what you have left is one line object that consists of two branches with a gap between those two branches where the deleted, middle part of the line used to be. Is that correct?

If so....

1. Is the part you want to delete a section of the line from one existing vertex to another vertex? or...

2. Is the part you want to delete some section of the line that is not both begun and ended at an existing vertex? If this is the case, how would you indicate what part of the line is to be deleted?

One more question:

How would you do what you want to do either in Arc or in Release 8?

A third way to do this in 9 today:

Suppose we have a line with six vertices: A B C D E F . We want to remove the C D segment, leaving two branches that consist of ABC and DEF.

1. Ctrl-click the line to select it. Ctrl-C to copy it. Shift-ctrl-click the line to deselect it.

2. Shift-Alt-click the line to choose it for editing in the Coordinates tab.

3. Select the A, B and C rows. Delete them. Update the record.

4. Back in the drawing, Ctrl-V to paste the line previously copied.

5. Alt-click that line on the A side to choose it for editing in the Coordinates tab.

6. Select the D, E and F rows. Delete them. Update the record.

You now have two lines that are the ABC and the DEF parts of the original line. Merge them if you like to make one line with two branches.

A fourth way that seems easy to implement: add the ability to double-click into the rightmost cell of a row in the Coordinates tab list to turn on the "new branch" symbol. You could then in one go simply denote new branches at the coordinates where you want first to delete a middle part of the line and then to have the remaining branch left, and then you could just delete the middle branch as I mentioned in my first post.

However, I'm curious as to what the work flow would be for this in other systems, such as Arc. Why invent a new wheel if there is already a good wheel to copy, right?

I'd also be curious to hear what the scenario is for why you would like to do this. It's not something I've seen before so I'm curious if perhaps there is an even better way of going about the ultimate task than looking at the lower level of how this could be implemented.

Aha... a late edit: yet another way to do this with 9 today:

1. Start with your ABCDEF line.

2. Draw two helper lines that intersect that ABCDEF line, one with a vertex in C and one with a vertex on D.

3. Run normalize topology. That breaks the ABCDEF line into branches at the intersections, with one branch being the segment CD.

4. In the normalize topology result, delete the two helper lines.

5. You can now delete the central CD branch as in my first post.

The normalize topology topic shows an illustration with a single long line broken into branches at intersections with other lines.


5,359 post(s)
#05-Sep-18 19:16

Forgot to mention: in that last, late edit procedure, the defaults will inherit the various fields into the normalize topology result. To preserve things like style, in the original drawing, delete the subject ABCDEF line and the two helpers. You can then copy the result from the normalize topology result and paste it into the original drawing and all the fields will be as they were for the one object that now has two branches. Whatever you did for the formatting based on those fields will be the same, with no need to mess around copying styles in the mfd_meta table, etc.


8,657 post(s)
#05-Sep-18 23:03

I agree with Klaus. He is missing tools on the Edit toolbar in Manifold 8.

I also often use these (though not all of them) and probably couldn't live without (some of) them in the long term.

Others will obviously differ, but for what it's worth, the tools I mainly use are 4 of the 6 in the first two groups: Add Coordinate, Delete Coordinate, Split Branch, Delete Branch. (I hardly ever use Add Coordinate on Segment or Delete Coordinate/Split Branch, nor the extend/leave/trim/split tools in the third group, for which I would rather use snaps.)

The specific operation Klaus mentions takes seven clicks in Manifold 8: Alt-Ctrl-click to select line for editing, click on Split Branch button, click-click on two vertices, click on Delete Branch button, click on the branch to delete, click elsewhere to leave edit mode. This feels efficient.

Does 9 need to do the same? Perhaps it could do even better, and the means could be more 9-like.

One suggestion based on Dimitri's workflow, a small but useful change:

  1. Shift-Alt-click the line to choose it for editing in the Coordinates tab
  2. Now in the drawing window, Ctrl-drag to select multiple vertices; this would also select the same vertices in the Coordinates tab
  3. Hit Delete
  4. Hit Ctrl-Enter to save changes

That's two clicks plus two keystrokes. But the main advantage is being able to edit vertices identified visually. It is usually not realistic to identify vertices by XY value. (Though as a side-note, being able to Ctrl-drag over vertices as above would make this more realistic and more useful, e.g. for finding the XY coordinates of a specific vertex.)



8,657 post(s)
#05-Sep-18 23:24

I would add to point 2: ...and if necessary scroll the tab list to show at least the first of them (where "first" may by necessity be arbitrary).

Also, besides Ctrl-drag, a single Ctrl-click in this context (in the drawing window) would also be useful, with similar effect.

And "drawing window" should probably include a map window with a drawing layer active.

Mike Pelletier

1,575 post(s)
#06-Sep-18 02:22

Wholeheartedly agree Tim. I'd just add more ways to select vertices like in 8 and the ability to add/delete from the selection. Deleting vertices is super common and can get complicated fast with complex shapes. The method you describe would be a very welcome improvement over 8's method and an important change for 9.

Also same here for what tools I use in the edit toolbar. I don't use 8 for CAD drawing type work so the extend/leave/trim tools don't get used but perhaps someday way down the road 9 could get into that world.

Another thought is for Mfd to minimize the amount of having to go back and forth between the map and the panes with a cursor whenever possible. Selecting rows to delete in the coordinates pane is an example.

Just have to say also that I'm very excited about the coming cartegraphy changes!


5,359 post(s)
#06-Sep-18 06:16

Looking forward to additions for cartography, too. There will be some improvements to style, etc.

There has been a set of commands desired for vector editing to add that have been waiting their turn for some time. Along with pushing forward with cartography, it's time for a cycle through vector editing.

Another thought is for Mfd to minimize the amount of having to go back and forth between the map and the panes with a cursor whenever possible. Selecting rows to delete in the coordinates pane is an example.

It has to be both however you want it, like selectback and interactivity between drawings and tables. Both have to be smooth, because sometimes it is more convenient visually in the map and sometimes more convenient with attributes in the table.

The grid in the coordinates pane is a very powerful thing. Extend it with a few more commands in the grid and with slightly improved simultaneous visual cues linking what's going on in the drawing to what's going on in the grid and it can be even way more powerful. It allows at a glance to work on the basis of info that can be less obvious in the drawing. And vice versa. Workflow has to be good and easy in both: the grid and the drawing.

Mike Pelletier

1,575 post(s)
#07-Sep-18 05:11

That all sounds great and I'm looking forward to making 9 my day to day GIS. The power in the grid is not something I'm seeing but I'll take your word for it :-)


5,359 post(s)
#07-Sep-18 06:46

I meant the power of how the grid could be used, not the simple way it is used now in the Coordinates tab.

The grid in the Coordinates tab is a new control Manifold developed for wherever lists appear. It has a lot to offer over the usual Windows approaches, with more headroom for fast, efficient, rich, compact, thread-safe, reliable, extensible, maintainable, and orthogonal user interfaces. Not a bad list of attributes for any control... :-)

New dialogs now use it, with existing dialogs being upgraded over time. The schema dialog, for example, could be (and will be) improved by using the new grid. It's a great platform for a richer experience in the Coordinates list.


6,300 post(s)
#07-Sep-18 10:30

BTW the ability to choose 'split branch' and 'duplicate branch', perhaps 'select coords of branch' from a context menu offered by the record indicator in the new grid control of the Coordinates tab would solve all my problems! Ehm, all my thread related problems ;-)


5,359 post(s)
#07-Sep-18 13:19

Agreed. Also need to be able to duplicate rows, copy/paste selected rows, move up/down and similar. I've sent all those in plus your comments as a suggestion.


8,447 post(s)
#22-Sep-18 09:39

Just a quick note: the cartography changes we are planning do include additions and extensions to vector editing like those discussed in this thread. The current cutting edge build,, deals with custom styles, and we have quite a bit of other additions for styles and for presentation in general (both maps and layouts), but we are going to improve editing as well.

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