Stake midpoint between two points

[John Thompson]

I just shot two section corners with the Triumph-LS and now I want it to tell me where to look for the quarter corner midway between them. Can someone give me a step-by-step tutorial for staking the midpoint between two points? I'm getting bogged down in creating an alignment. Surely this is simpler than I'm making it. Thanks for your help.

 

[Matt Johnson]

This can currently be done with the Divide Line CoGo function. Select the two endpoints and enter 1 point to be created:

From here press create or click the diagram for a preview:

Pressing create in this screen will create the point L1 at the midpoint, you could then stake it.

 

[John Thompson]

OK, so now if you click Create it will create a point named L4 at the midpoint. I can then go to Stake, select Points mode, select point L4, and it will take me there. That seems like a lot of clicks. If instead I click the Stake Now button on the Divide Line screen it asks for an alignment name, I hit OK, and it gives me my current station and offset from the line, but the white boxes for North/South, East/West, Cut/Fill, CTT, and DTT all say "--". I want them to tell me how to get to the midpoint.

 

[Matt Johnson]

Yes I see this too:

The problem is that Stake mode is defaulted to the Stake Here mode:

rather than the Alignment Points mode. After changing to Alignment Points mode it is also still not selecting the created points to be staked. I will request these items be fixed.

 

[John Thompson]

Thanks, Matt.

So here is a related question. What if the quarter corner I'm searching for is not at the midpoint? I have shot the SE and SW corners of Section 30. Now I want it to take me to a point on line between them, but 40.26/(40.26+20.13+20.05)*(measured distance between corners) from the SE corner.

I suppose I could solve this problem with a localization, but a COGO routine seems faster and simpler.

 

[Matt Johnson]

Thanks, Matt.

So here is a related question. What if the quarter corner I'm searching for is not at the midpoint? I have shot the SE and SW corners of Section 30. Now I want it to take me to a point on line between them, but 40.26/(40.26+20.13+20.05)*(measured distance between corners) from the SE corner.

I suppose I could solve this problem with a localization, but a COGO routine seems faster and simpler.

I would use calculator to figure the distance along the line you need, be sure to try out the MS and MR buttons for storing and recalling values. Also the calculator is currently being improved to support parenthesis and line operations. Once you have the distance along the line there are several options:

• You can use the Alignment Stake-Here mode as shown above and press Stake Line. In this mode you will be shown your current station and offset as you move around. You would just need to navigate to the desired station.
• You can create a point along the line using the CAD tools. Create a point at the intersection of a circle with the radius of your distance and your line. The CAD functions are available in the review screen by pressing Draw, these are still somewhat in development. Midpoint isn't currently working correctly so we didn't mention it earlier.
• You can use the Divide Line function and change "Points, n" to "Segment Length" by clicking it
• You could use the CoGo Offset function and enter an offset of 0 and the distance along the line that you need.

 

[John Thompson]

Thanks, Matt.

 

[Matt Johnson]

Thinking about this more it would probably be good for us to create a Proportion tool in the future for situations like you describe.

 

[John Thompson]

On a related note, I have had a few times recently when I needed to stake a point that is equidistant from two points but not necessarily on line between them. In other words I need to stake a point on the perpendicular bisector of the line joining the two points. Is there any way to do that?

 

[Kelly Bellis]

Circles of equal radius drawn from each of the two points will have two solutions/ intersections - pick the one you want

 

[Matt Johnson]

Also the Offset function can do this, divide that inverse between the two points in half and use it as the D variable.

 

[Mikhail Drakin]

Matt, in Stake Here mode, North/East, CTT, DTT, etc whiteboxes should not be filled, it is correct behavior - when you stake along a line, onle left/right indication makes sense. Also, each time you press "Stake Now" in CoGO Divide, mode is automatically switched to Stake Here (as it was requested some time ago), so the only way is going to Prepare Stake screen and switching mode back.

On the other hand: there indeed is a bug with stake step ignored when creating an alignment from the Divide screen - thank for finding it. Also, the alignment will always have starting and ending points, so it doesn't suit for this specific task of staking a single point. I wouldn't use alignments or line staking for this task, just conventional CoGo tools. Also, choosing created point for staking may be faster in stake "from map" mode, avoiding searching for point in the list.

 

[Matt Johnson]

Hi Mikhail, I realize this is the correct behavior for Stake Here mode. My thought was to switch to Alignment Points automatically when Stake Now is pressed from the Divide Line function. Do you remember why it was changed to Stake Here mode? For staking a line the mode should be automatically set Stake Here mode but I don't see any reason for this with the Divide Line function.

 

[Mikhail Drakin]

It was a request from PLS team. I don't exactly remember if it was in this forum or in its previous incarnation, or even during a meeting. I'll try to find a link. "Divide Line" is the screen which is called by Stake Line menu command.
Of course I can create separate screen for the latter command, but it was general request that all command leading to creation of alingments switched to Stake Here mode immediately. If someone doesn't want Stake Here mode, they can use "Create Alignment" button. It will still require multiple clicks, but these clicks are more straightforwad.

 

[Matt Johnson]

I think I requested Stake Here mode be the default but I was just wanting this when staking a line without any intermediate points being created. I would recommend if "Points,n" is set to 0 then default to Stake Here, if >0 then default to Alignment Points mode.

 

[Mikhail Drakin]

Yep, I've found it. https://support.javad.com/index.php?threads/cogo.47/#post-309
The problem is that we'll need to add new screen for this to work, as currently this screen is used to just stake line between two points without editing number of points.
The differentiation is already handled with Stake Now or Create Alignment buttons.
Besides, I don't remember other reports that asked for creating alignment and switching to it in points mode except for this one, and here it also won't save the problem.
So I'll put it (creating new UI for selecting points for staking line) in the todo list, but I don't think it's high priority issue.

 

[Matt Johnson]

The problem is that we'll need to add new screen for this to work, as currently this screen is used to just stake line between two points without editing number of points.

When I choose Stake Line -> Line By 2 Points in the collect prepare screen, it opens Divide Line function and the number of points can be edited. If I choose Polyline From Map or Line Segment From Map, you are correct that the number of points can't be changed and it just stakes the line with Stake Here mode. I think this is still the desirable functionality for Polyline From Map or Line Segment From Map. I'm not sure I understand or see why a new screen would need to be created. I think the NEXT and PREV buttons in the stake action screen work for selecting the points to stake. In John's case to stake the midpoint he would just divide the line with one point and then press NEXT once to get the midpoint when in the Alignment Points mode.

 

[Mikhail Drakin]

When we implemented "Line By 2 Points", we were targeting at minimum possible clicks - I even eliminated prompt for saving the alignment. You suggest that I require the user to each time reset points number to zero and carefully examine the screen contents, otherwise they will have to, if overlooked nonzero points number, manually erase created points and repeat the operation. That's why, if you want that both operations look the same but one of them at Stake Now switches to Stake Here, and other - to Stake Points, we will need to have two screens looking differently enough that they will not be confused. Still I don't understand why in the (rare as it seems to be) case when you need to immediately stake alignment points, one cannot use the already existing "Create alignment" button which requires 3 more clicks, but lets review the resulting points and does not switch to Stake Here mode. Another option is using simply Create and then choosing points to stake with "From Map" mode.

Considering the midpoint task, there will be two or three new points created with "station/offset" name instead of only one, even if we switch to Stake Points mode, because the first alignment point is always created in this mode after switching to stake action screen.

 

[Matt Johnson]

Yes I like the From Map option we have and this is one good way to do this. I think the problem most users would have with the Create Alignment method is that this is more complicated (more options and settings) and most users haven't taken the time to learn how to use it yet.

 

[John Thompson]

I like Matt's idea of a Proportion tool. It would be nice if it could crunch the numbers for double proportioning a section corner, too.