Divide Line

John Thompson

Well-Known Member
CoGo > Stakes > Divide Line

I like this feature and used it a bunch today, and there are a few tweaks that I think would make it more useful.

1. "Points, n" defaults to 2, but it should default to 1. I almost always use this feature to calculate the midpoint between two points, but I don't think I've ever used it to divide a line into thirds. Personally, I think it would be more intuitive to specify the number of segments instead of the number of points, but most of the time I can do that much math in my head. So maybe default to two segments instead of two points.

2. It would be nice if I could specify "Points, n" and the resulting segment length would be displayed. Similarly, if I specify Segment Length to have "Points, n" displayed. (Or segment length and number of segments)

3. The Code of the resulting point(s) should be DefCode. It might be nice to be able to specify the Code, but DefCode is most likely fine. Currently, the points are created with the code of the last saved point. I'm unlikely to want a calculated design point to have the same code as any point I just surveyed.

4. A single-proportion tool would be super handy. If I could enter the record distance between P1 and P2 and the record segment length and number of equal segments, that would be awesome.

5. After I press Create (+) and the popup (which isn't necessary) shows the created points, the Create (+) button ought to be disabled until I make any changes to P1, P2, Segment Length, etc. Otherwise if I press it again, it creates a duplicate set of points with the same coordinates.

6. Better yet, after I press the "Create+" button, it could be replaced with a "Stake" button that stakes all of the resulting points from nearest to farthest, which is always what I want to do next.
 

Andrey Zhiganov

Active Member
JAVAD GNSS
Hello John.

1. "Points, n" defaults to 2, but it should default to 1. I almost always use this feature to calculate the midpoint between two points, but I don't think I've ever used it to divide a line into thirds. Personally, I think it would be more intuitive to specify the number of segments instead of the number of points, but most of the time I can do that much math in my head. So maybe default to two segments instead of two points.

...

3. The Code of the resulting point(s) should be DefCode. It might be nice to be able to specify the Code, but DefCode is most likely fine. Currently, the points are created with the code of the last saved point. I'm unlikely to want a calculated design point to have the same code as any point I just surveyed.

...

6. Better yet, after I press the "Create+" button, it could be replaced with a "Stake" button that stakes all of the resulting points from nearest to farthest, which is always what I want to do next.

It's not difficult to do but I would like to see some comments from other surveyors who works with this CoGo task.

2. It would be nice if I could specify "Points, n" and the resulting segment length would be displayed. Similarly, if I specify Segment Length to have "Points, n" displayed. (Or segment length and number of segments)

...

5. After I press Create (+) and the popup (which isn't necessary) shows the created points, the Create (+) button ought to be disabled until I make any changes to P1, P2, Segment Length, etc. Otherwise if I press it again, it creates a duplicate set of points with the same coordinates.

Added to the to do list.

4. A single-proportion tool would be super handy. If I could enter the record distance between P1 and P2 and the record segment length and number of equal segments, that would be awesome.
I'm not sure to understand correctly. Could you describe your workflow with "single-proportion tool".
 

John Thompson

Well-Known Member
Thanks, Andrey.
Here is an example.
9590

50'x140' lots in a residential subdivision. I find monuments at the NE corner of Lot 1 and the NE corner of Lot 8. The plat shows they are 350' apart. I find monuments 350.65' apart. I need to divide the excess 0.65 feet across 7 lots and calculate the locations of the intermediate lot corners, giving each lot its proportionate part of the excess.

When I tap on Segment Length, it could bring up a calculator where I enter the record distance between P1 and P2 (350 feet) and the number of equal segments (7) and it calcs the coordinates of all the lot corners.
 

Nate The Surveyor

Well-Known Member
Suggest: it could divide by number of points, or number of spaces. Check box.
And A pro rate check box, when checked, that allows you to enter record dist between end points. This would satisfy both systems of thought, and add pro rate.
N
 

Andrey Zhiganov

Active Member
JAVAD GNSS
When I tap on Segment Length, it could bring up a calculator where I enter the record distance between P1 and P2 (350 feet) and the number of equal segments (7) and it calcs the coordinates of all the lot corners.
John, we already have a standart calculator:
9591

9592

9594


Ok. So far I will add the follow points:
- divide by segments count
- default value to 1 for divide by points count
 

Aaron S

Active Member
I'd like to add a bit to John's example above. This "divide line" example shows the lots all being of equal size, which happens frequently. But, there are situations where the missing monument will not be midway between - or at an even increment - between found monuments.

In the western states, the PLSS system will regularly divide a line using references to historic measurements (usually well over 100 years old) so that the overall length of an east/west line is 5,200' (for example) as shown on the old map between found monuments, and another point between those two monuments at 2,640' from the east end of the line and 2,560' from the west end. Now today we find those two monuments to be 5,231' apart... we would need to calculate a point that is (2,640/5,200)*5,231 from the east end and (2,560/5,200)*5231 from the west end.
 

James Suttles

Active Member
The calculator example only works if each lot is of equal size. Often times, they will be unequal lengths, so a constant has to be calculated and applied to each distance, so not sure there is an easy way to create a program to handle that situation. The 350' in our example, works because the 7 lots are equal distances, but will not work if the distances are not equal. At that point you have to apply the measured distance, divided by the recorded distance, to get the amount needed to apply to each lot.

So with that said, looks like we will be doing the math in those situations. To further help understand the issue, here is a text book example.

http://immersion.gmu.edu/forestry/s...nit01sec02wireframes/rol-u01-s02-ss01-p01.htm

Great idea though. I had not thought of using the calculator to figure the distances like has been shown, but will be using in the future.

Thanks
 

John Thompson

Well-Known Member
Thanks, Andrey. I didn't see that calculator button already there. That works. It might help if Segment Length defaulted to the Distance between P1 and P2 so that I could press segment length, calculator, and /7 and I wouldn't have to read the fine print and type in the total distance. and risk a blunder. So have Segment Length default to the total distance but have Points, n default to 1 (2 segments) would be my preference.

As for a more general proportion tool that would allow dividing a line into two unequal segments, I would definitely use it.

A tool that divides a line into more than two unequal segments would also be useful, but might be better as a separate tool. For now, I import a polyline with segments of the record distances and use a localization to translate, rotate, and scale it.
 

John Thompson

Well-Known Member
Ok, I'm a little slow at this. That calculator works fine for calculating the quarter corner on a closing section (dividing the line into two unequal segments).

Just type in the total distance from P1 to P2. If this were the default value, that would be better.
9595


Then press the calculator button and type in the record distances (40 chains and 80.12 chains in this example).
9596


The quarter corner is calculated at C1.
9597

This also calculates C2 near P2, but delete it.

Just make sure that P1 and P2 are not reversed. A swap button like the Inverse screen has would be nice.
 

Matt Johnson

Well-Known Member
5PLS
50'x140' lots in a residential subdivision. I find monuments at the NE corner of Lot 1 and the NE corner of Lot 8. The plat shows they are 350' apart. I find monuments 350.65' apart. I need to divide the excess 0.65 feet across 7 lots and calculate the locations of the intermediate lot corners, giving each lot its proportionate part of the excess.

When I tap on Segment Length, it could bring up a calculator where I enter the record distance between P1 and P2 (350 feet) and the number of equal segments (7) and it calcs the coordinates of all the lot corners.

The current Divide Line CoGo function can already do this. Pick points P1 and P2 which measure 360.65' apart and then choose to divide it with 6 points to create 7 equal segments. There is no need to enter a record distance.
 

Andrey Zhiganov

Active Member
JAVAD GNSS
As for a more general proportion tool that would allow dividing a line into two unequal segments, I would definitely use it.
I will add this as a new CoGo task.

A tool that divides a line into more than two unequal segments would also be useful...
So far I cannot decide how to do it properly. I will return to this task in the future.
 

Matthew D. Sibole

Well-Known Member
5PLS
What I would like to see is the ability to prorate or scale a group of points. Say I have a subdivision where all front lot corners were supposed to be 50’ wide. I calculate those in the office. I get to the field and all of the corners are off by 0.2’. I would like to hold one of those corners and scale the precalculated corners to match what I found in the field.
I know I can do this is localization but a scale CoGo feature I think would get used more often.
 

Steve Hankins

Active Member
5PLS
What I would like to see is the ability to prorate or scale a group of points. Say I have a subdivision where all front lot corners were supposed to be 50’ wide. I calculate those in the office. I get to the field and all of the corners are off by 0.2’. I would like to hold one of those corners and scale the precalculated corners to match what I found in the field.
I know I can do this is localization but a scale CoGo feature I think would get used more often.
I agree with Matt. A scale feature, along with the current translate and rotate features would be very productive and useful in the field!!
 

John Thompson

Well-Known Member
Yesterday I used the new and improved Divide Line function for the first time. Works great! I really like the stake button on the result info window. The only remaining tweak I would ask for is to give the resulting points code Defcode (#3 in original post). Thanks for fixing this. I appreciate it.
 
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