Activity Feed › Discussion Forums › Strictly Surveying › Weighted Mean
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Nate The Surveyor, post: 392468, member: 291 wrote: If the legal mid, is not at the math mid pt…
It will be a fractional section, the controlling corners don’t exist so you use the weighted mean to get an interior line.
I don’t see very many of them, lakes, rivers, ocean, up against an irregular senior line of some kind. -
Mr Moe, in those circumstances… You have to have more information…
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Rankin_File, post: 392517, member: 101 wrote: Careful… You’re not just slapping math on the ground are you?
No, there was a surveyor before me; just checking his math…
His math checks with mine; but there is a definite difference in the ancient bulkheads, about 6 feet away; into my client’s neighbor’s property. My client’s wall is stones and concrete stacked up and the neighbors is an old 6″ concrete wall.
My clients deed says the south 100′ of Government Lot 7. A 3/4″ iron pipe, in the wall on his north line is 0.02′ south of the line parallel and 150′ from our calculated line between government lots 7 and 8.
Is the split in the bulked an indication of where the line should be? The walls were there when my clients father in-law purchased the property in the 1970’s. The father in-law was a surgeon in Tacoma and only spent a couple weekends a year at “The Cabin”.
The occupation, on both sidelines of this property, is thick, overgrown brush.
I hope everyone has a great day; I know I will! -
RADAR, post: 392525, member: 413 wrote: No, there was a surveyor before me; just checking his math…
His math checks with mine; but there is a definite difference in the ancient bulkheads, about 6 feet away; into my client’s neighbor’s property. My client’s wall is stones and concrete stacked up and the neighbors is an old 6″ concrete wall.
My clients deed says the south 100′ of Government Lot 7. A 3/4″ iron pipe, in the wall on his north line is 0.02′ south of the line parallel and 150′ from our calculated line between government lots 7 and 8.
Is the split in the bulked an indication of where the line should be? The walls were there when my clients father in-law purchased the property in the 1970’s. The father in-law was a surgeon in Tacoma and only spent a couple weekends a year at “The Cabin”.
The occupation, on both sidelines of this property, is thick, overgrown brush.
Maybe.
The pipe is 50′ too far north?
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Dave Karoly, post: 392527, member: 94 wrote: The pipe is 50′ too far north?
No, the pipe is on the opposite side and it’s within two hundredths of the line; according to my GPS, using the RTN….
Wait a minute, you might be right, it could be 50′ off. After all; it only took me 5 minutes, after climbing up there, to get my shot. [SARCASM]That’s way to quick to be accurate. [/SARCASM]
I will be out there again, to finish up. I will hit again:stakeout:, along with all my other control, just to be sure…:grinning:
I hope everyone has a great day; I know I will! -
RADAR, post: 392528, member: 413 wrote: No, the pipe is on the opposite side and it’s within two hundredths of the line; according to my GPS, using the RTN….
Wait a minute, you might be right, it could be 50′ off. After all; it only took me 5 minutes, after climbing up there, to get my shot. [SARCASM]That’s way to quick to be accurate. [/SARCASM]
I will be out there again, to finish up. I will hit again:stakeout:, along with all my other control, just to be sure…:grinning:
That is what I thought you meant but wasn’t sure, your post was unclear, “his” north line.
Without more evidence, the break in the bulkhead likely does not show possession since there is no wall or fence on the line in question. I would probably stake the record line since there is an absence of ambiguity. If you had evidence that the break occurred because of a survey or actions of the parties establishing the boundary then it could be persuasive but I don’t see that here.
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Nate The Surveyor, post: 392523, member: 291 wrote: Mr Moe, in those circumstances… You have to have more information…
Not really, assuming a virgin section then the weighted mean is the solution,,,,,
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RADAR, post: 392528, member: 413 wrote: No, the pipe is on the opposite side and it’s within two hundredths of the line; according to my GPS, using the RTN….
Wait a minute, you might be right, it could be 50′ off. After all; it only took me 5 minutes, after climbing up there, to get my shot. [SARCASM]That’s way to quick to be accurate. [/SARCASM]
I will be out there again, to finish up. I will hit again:stakeout:, along with all my other control, just to be sure…:grinning:
Here is a couple of examples of weighted means from a seminar I attended several years ago, either by Steve Parrish or Jim Dorsey. I got the same answer, N 87å¡59’13″W for the mean bearing.
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Weighted Mean for this Problem:
N 88å¡03’11Û W 1317.47′
N 87å¡50’19Û W 586.90′The North line is longer than the South line therefore the North bearing has more weight. How much more weight?
1317.47’/586.90′ = 2.2448 more weight.
Convert both bearings to decimal degrees and multiply by it’s weight.88.053055 * 2.2448 = 197.661499
87.838611 * 1 = 87.838611Add the results and divide by the total weight.
197.661499 + 87.838611 = 285.500110 / 3.2448 = 87.986967
Convert back to å¡ ‘ ” = 87å¡59’13”
You get the same answer by multiplying each bearing by it’s length (very big numbers), adding them and dividing by the total length, but you get a better idea of the weight by converting to a unit number and the weighted multiplier.
Paul in PA
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Rankin_File, post: 392517, member: 101 wrote: C
Careful… You’re not just slapping math on the ground are you?
No need for math when you have autocad….
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Jim_H, post: 392597, member: 11536 wrote: No need for math when you have autocad….
With AutoCAD you learn nothing of what you are doing. You learn by doing the math with the simplest tools possible.
After all you do not get to take your whole office into the NCEES exams.
If you don’t know the basics, how do you mentor/teach someone else?
Paul in PA
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Paul in PA, post: 392635, member: 236 wrote: With AutoCAD you learn nothing of what you are doing. You learn by doing the math with the simplest tools possible.
Knowing the math is nice, but it has practical limits. If I had to “know the math” behind calculating positions from GPS observations, I’d be dead in the water. I think the AutoCAD solution is actually better at demonstrating the weighted mean principle.
I still remember the day I first saw a bearing-bearing intersection solved in AutoCAD (R9 on a 286 PC). Suddenly the images I’d had in my mind’s eye for years were right in front of me, and this made the process so much easier.
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Jim_H, post: 392597, member: 11536 wrote: No need for math when you have autocad….
[SARCASM]Folks who slap AutoCAD on the ground need to be slapped to the ground…[/SARCASM]
Rankin_File 2016 -
Dave Karoly, post: 392467, member: 94 wrote: The weighted mean bearing only requires the two (roughly) parallel lines, the distance between them is not relevant. It is used to get a centerline bearing on a fractional section where one of the relevant quarter corners was not set.
You simply traverse the first from point 1 to point 2, then the second from point 2 to point 3 then inverse point 1 to point three to get a weighted mean bearing.
Thank you! I learned that in Paul Cuomo’s class 25 years ago. I have forgot more than I have learned over the years. Jp
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It depends upon how the settings have been made on your AutoCad.
Was trying to explain that to a tech that was not getting the same results as my COGO program.
His two decimal placed coordinates were less than par to even show monuments along a straight line to display the correct bearing from monument to monument.
They were close, just not the same. -
Paul in PA, post: 392635, member: 236 wrote: You learn by doing the math with the simplest tools possible.
Paul in PAJim Frame, post: 392646, member: 10 wrote: Knowing the math is nice, but it has practical limits. I think the AutoCAD solution is actually better at demonstrating the weighted mean principle.
Those are both up to date teaching principles. AP Calculus teachers are trained to teach using the V-NAG technique. That means teaching each concept from a Verbal perspective, a Numerical perspective, an Algebraic perspective, and a Graphical perspective. The order can vary from topic to topic, but students really learn and understand when teachers use all four approaches on every topic. So, one technique augments another instead of replacing it.
Here’s what I want to do, here’s how it looks on a coordinate system, here’s the algebra that leads to the calculus, and here’s a numerical example. When a teacher can teach all four perspectives, he knows his stuff and students wiil know their stuff when they’re finished.
I’ll bet that really good mentors do something similar.
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Jp7191, post: 392656, member: 1617 wrote: Thank you! I learned that in Paul Cuomo’s class 25 years ago. I have forgot more than I have learned over the years. Jp
Since were giving credit, which I’m all for, I learned it an LSAW conference a few years ago from Jim Coan.
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Jim Frame, post: 392646, member: 10 wrote: Knowing the math is nice, but it has practical limits. If I had to “know the math” behind calculating positions from GPS observations, I’d be dead in the water. I think the AutoCAD solution is actually better at demonstrating the weighted mean principle.
I still remember the day I first saw a bearing-bearing intersection solved in AutoCAD (R9 on a 286 PC). Suddenly the images I’d had in my mind’s eye for years were right in front of me, and this made the process so much easier.
As I said, “You do not get to drag your AuotCAD equipped computer into the NCEES exam site. You can however take a very basic calculator.
Paul in PA
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