Replies to This Discussion

Permalink Reply by Mac Davis on May 23, 2009 at 11:48

OK, a little humor. It's a joke. Nobody get your shorts in a wad over it.

I have this picture of walking into the assessor's office and discussing this.

"How did you calculate the area of my plot?"

"We type the lengths of the 4 sides into the computer and it gives us a number."

"Well, the length of the 4 sides is not enough to calculate the area of the plot. What formula does the computer use?"

"Huh? There's no formula, the computer does it. It's got to be right, the computer calculated it."

"But the 4 sides aren't enough info to calculate the area. Where did the computer program come from?"

"Huh?"

---skip several steps, lots of time and arguments, talking to a supervisor.

"Huh?"

"Well, where did the computer program come from?"

"It was here when I got here in '87. Don't worry, we know it's right because we've been using it for so long."

"But you calculated 3 acres, and Brahmagupta's equation proves it can't be more than 2.5 acres."

"Who is Brother Goopa?"

"Brahmagupta. He's an Indian mathematician who derived the equation for the area of a quadrilateral."

"Well, that explains it. They use a different surveying system in Europe than we do here in America."

"Huh? No, no, it has nothing to do with surveying system, it has to do with the area of a quadrilateral."

"A quadriwhat? They use Kilometers and liters over there in Europe, it messes up the numbers when you come to the US. Don't worry, we do this all the time and know what we're doing."

"What kind of program is it you're using? Is it a commercial surveying program?"

"No, it runs on a PC."

"No what language is it written in? How do you run it?"

"I think it's Microsoft Word."

"Does it put up some horizontal and vertical lines on your screen and you fill in some of the boxes?"

"OK, that's probably a spreadsheet. It's probably Microsoft Excel."

"It does say something about Excel, but it's not a spreadsheet, you don't use any paper, it's all on the TV and keyboard."

"Well, who wrote the program? Who can discuss it?"

"Alice, where did the acreage program come from?"

"It was here when I got here."

"Well, who maintains it?"

"It doesn't need any maintenance. We just copy it from computer to computer."

"Does anyone work with it when you have problems?"

"Well, I think Johny Carter was the last one who worked on it."

"Who's he?"

"He's Edna's nephew, cute kid. Real bright for a 13 year old. I think he's married and has kids of his own now. He was real smart. He had to do something to it when we stopped using VisiCalc. "

...

• ▶ Reply

Permalink Reply by Mac Davis on May 23, 2009 at 14:04

Given the lengths of the 4 sides, Brahmagupta's formula gives the EXACT maximum possible area the plot can be. The actual acreage may be smaller, but it CAN NOT be more.

There WILL be a configuration of those 4 sides lengths that gives you a plot with the EXACT acreage calculated by by Brahmagupta's formula.

It is NOT an estimate. It is the EXACT calculation of what the maximum area can be given the 4 sides. It gives you an easy check on someone's calculation. If someone's calculation is higher than what the formula gives you, their calculation is WRONG.

If a professional, licensed surveyor gives you the 4 sides and an acreage that's larger than what Brahmagupta's formula gives you from the 4 sides, the surveyor is RONG, wrong. He's calculated wrong.

The actual acreage CAN be smaller. As I've said, it's an upper bound, not the exact calculation.

There are plenty of people who will try to cheat you. This is one way to check on the accuracy of their estimates.

It's quite common for someone to have the lengths of 4 sides, but no information on the angles. Being able to disprove someone's calculated acreage is a good thing.

Several people have suggested other estimation methods for the size of the lot, including multiplying the average length of pairs of opposite side, or squaring 1/4 of the perimeter. Lots of people use the estimates. I believe that Brahmagupta's formula is going to be more accurate than either of these.

As an example of how this is useful, we've already shown that the assessor has an acreage for Ray's lot that is not correct if Ray's length measurements are correct.

By all means, if you have the angles or latitudes and departures, make an exact calculation. Then when you're through, check that you haven't come up with an area larger than Brahmagupta's formula. If you have a survey done, check the area calculation with Brahmagupta's formula. Surveyors make a LOT of mistakes.

Latitudes and departures are simply Cartesian coordinates measuring a line. e.g. a line is +70.7 feet N +70.7 Feet East vs. 100 feet at 45 degrees. No mysteries there once you get accurate measurements. There's no magic about the calculations. Give me the recorded bearings and distances, and I'll calculate the area for you in about 10 minutes. Or give me the angle of any corner. My calculations will be exact given that your measurements are correct. (or correct to the number of decimal places Openoffice uses.)

• ▶ Reply

Permalink Reply by Mac Davis on May 26, 2009 at 19:12

I must admit this has become extremely humorous.

My qualifications are irrelevant. The correctness of my information is what matters.

Please check out ad hominem

If you do not believe my statements, disprove them. Can you explain how any plot of land can have an area larger than that given by Brahmagupta's formula? Please produce an example of such a plot of land. If my statements are incorrect, I'd like to know about it.

The maximum possible acreage is definitely relevant. If someone gives you figures for a lot, and the area is larger than what is mathematically possible, you'd better check your numbers.

If I had a court case, and the opposing party's surveyor had made a survey where his numbers indicated an area larger than Brahmagupta's formula allows, I would figure out where his numbers (or my calculations) were wrong, and then get a surveyor who knew what he was doing to testify on my behalf.

Are you seriously suggesting that if a surveyor produces a survey with mathematically impossible numbers, I should accept it? Or should I dig into the issue further and try to figure out where one of us has made a mistake?

Yes, it would be very good to have a set of exact lengths and angles or whatever else it takes to calculate acreage. A professionally done survey is a nice thing to have. It would still be a good idea to sanity check his measurements and calculations.

However, a lot of people want a rough calculation of what their acreage is, or they want to doublecheck what they've been told by a professional, landman, assessor, etc. Being able to get a quick estimate of the acreage is a good thing. It may tell you whether it's worth considering a lease, challenging an assessment, etc.

There are dozens of posts on this site asking how to do an estimate of acreage, given just the four sides. Lots of guestimate formulas have been given. I think it's important to figure out how accurate or inaccurate these formulas are.

As for surveyors not making mistakes, have you never done a survey and found that a previous surveyor had made an error in surveying? Aren't there lots of cases where a property line is disputed? Have you never had a case where your results differed from another surveyor's results?

• ▶ Reply

Permalink Reply by Mac Davis on May 29, 2009 at 21:06

As I've said several times before, "maximum possible" acreage does not necessarily indicate the acreage you have. That's simple English.

I'm tired of typing "Maximum possible" and "Brahmagupta's formula," so let's just call it the "B number. If you have the lengths of the sides, but not any angles, this B number is good to know.

In this case, Ray's measurements are 146' + 127' + 121' + 39'. The B number is 0.2382 acres. The landman says 0.198 acres. The landman's number COULD BE RIGHT, but it could be up to 17% or 0.04 acre low. Remember, this thread is about Ray's measurements and what Ray should do.

Ray can now consider whether it's worth the time and effort to question the landman, go the assessor's office for a plat, do some more measurement on his own, etc. Run some numbers, calculate how many dollars the error COULD be and decide whether it's worth the effort.

If the landman's number had been close to the B number, I'd be tempted to accept the number without further argument.

By the way, my own lease lists an acreage slightly higher than my calculated B number, so I don't need to question it.

If you think their acreage number is wrong, question it. Maybe they'll give you some information you don't know, such as that your mineral rights don't include a strip along the road, or that one of your measurements is wrong. Maybe they'll give you a map that shows you their measurements, and you'll see they're right. Maybe they'll give you a map and you can show them where they're wrong. (For instance, they might have a map of the wrong piece of property.) You may convince them one of their measurements is wrong. Be friendly and say you just want to be sure the number is right.

If you're not convinced, try digging up some more info. Consider if it's worth hiring a professional surveyor. If you had a significantly large plot of land, you should consider hiring a professional surveyor to get a survey even if you think their numbers are right. Even if it doesn't make a big difference on the bonus payment, it could make a big difference in royalty payments.

Remember, if you sign a lease, it may indicate that the payments will be based on x acres, no matter what the real acreage is.

Does anyone have an idea what a professional survey tends to cost? I understand it will probably vary with size, terrain, travel time, etc.

By the way, the B number also indicates that the assessor's number is wrong. It's high by at least .254-.2384 or 0.0156 acre or 6.5%. It could be off more. Ray can decide whether it's worth digging into the assessor's number, but I doubt it would make any significant difference in the
appraisal or taxes.

And isn't it an amazing coincidence that the assessor's number is high and the landman's number is (possibly) low? 8-)

(This all assumes that the 146' + 127' + 121' + 39' number is correct)

• ▶ Reply

Permalink Reply by Mac Davis on June 9, 2009 at 9:29

Is anyone willing to comment on what professional surveys have cost them?

I just had a phone conversation with the assessor's office that reminded me of the hypothetical above. I called up and said I wanted to get a copy of the plat for my property. The lady sounded like I'd just walked off the UFO and nobody had ever asked this before.

I really just wanted to know which office to go to, working hours, etc., but she seemed to be very confused about the concept.

• ▶ Reply

Permalink Reply by BirdDawg, plain ole' idiot on June 9, 2009 at 9:52

Mac,
If your land is in a recorded subdivision, then it should not any problem to get a copy of the subdivision plat showing your lot. If it is not in a subdivision, then there may not be a "plat" on file at any office at the courthouse. By the way, in Louisiana the Office of the Clerk of Court is where you should find the original subdivision plats and any other recorded plats of property. Please remember that tax acessor "plats" (I prefer to call them sketches) are not official unless they are a copy of an actual survey.

Surveys can vary from a few hundred dollars for a lot in a subdivision to several thousand dollars for large tracts. If you tell me the general area or parish you are in I would be glad to send you a list of surveyors in your area. Generally you are better off getting a surveyor that has done a lot of work in your vicinity, it can save you money.

• ▶ Reply

Permalink Reply by Mac Davis on June 9, 2009 at 16:13

Thanks.

I don't need a survey myself right now. I know my acreage close enough to not matter. Luckily, my land is close to rectangular and I know the measurements. I just figured it's useful for people to know in general.

However, names in the Keithville area would be appreciated.

I guess a copy of deeds, deed restrictions, and other such info would be a good idea, too. I guess leases are filed somewhere, too. Is such info easy to obtain, too?

• ▶ Reply

Permalink Reply by BirdDawg, plain ole' idiot on June 9, 2009 at 16:53

Mac,
All of that info is in the Clerk of Courts office in the parish the property is in. A lot of people go to the tax acessors office thinking they are going to get the real info.

The real info is in the Clerks office, in the conveyance books. Also, if you are in a subdivision, all deed restrictions, or subdivision covenants, will be recorded with the subdivision plat. Some times tracts that are not in a subdivision will have deed restrictions, and they will be mentioned on the face of the deed. And that can be found at the Clerks office. The personnel in the Clerk of Courts Office should help you to learn how to research the records. They are public employees.

I will check on names and adresses of surveyors in your area.

Leases are also filed in the Clerks office. With just a little help, you should be able to "run the records". Most Clerks offices now have computers now that make it much easier to check all activity back to a certain date. Prior to that you will need to check the direct - indirect indexes regarding what you are looking for. This may sound confusing, but it really isn't. With a little guidance from the clerks office personnel, you will pick it up pretty quick.

• ▶ Reply

Permalink Reply by Mac Davis on June 9, 2009 at 17:18

Merci amigo.

We had no mineral production in the past 10 years, so there should be no old leases of interest. (There is a pipeline in our section, but no producing wells.)

Some deed restrictions were recently changed, long after the deed was recorded, so it will be interesting to see if they have the restrictions linked to the deed.

• ▶ Reply

Permalink Reply by BirdDawg, plain ole' idiot on June 9, 2009 at 17:23

Mac,
That would be interesting to see. Usually for deed resteictions to be changed it would take a majority of the landowners involved to make the change. Let me know what you find out.

• ▶ Reply

Permalink Reply by Mac Davis on June 9, 2009 at 19:32

Yes, all or almost all, of the property owners in the subdivision signed off on the change in deed restrictions. (Or covenants, or whatever the heck the appropriate term is.)

• ▶ Reply

• ‹ Previous
• 1
• …
• 3
• 4
• 5
• Next ›
• Page