PADI tables finally going away?

[Kevrumbo]

Again, so??

Any calculus equation can be expressed as a discrete equation to any level of precision you wish to utilize. There is no inherent superiority to one method over the other and each is superior under the right conditions.

But even more to the point, the diver isn't doing the math, so the method of generation is immaterial.

Because a table MAY have been produced using continuous functions doesn't make it analog. It doesn't make an equation 'analog.' There application of the term "analog" in mathematics is for analogical models in applied mathematics, which do not have a place here. The mathematical model is not trying to compute something else using nitrogen loads, tissue compartments and the like to stand for something else. They are standing for themselves as abstractions to the source/target. You are not using the output of one equation to represent the output of a different target set.

Even more to the point, modern tables are computed using computer programs, not people sitting down doing calculus, so the values come from discrete functions just as the values on a PDC do.

So what are you trying to argue here? Because your intended point is eluding me entirely.

Analogical models are a method of representing a phenomenon of the world, often called the ‘target system’ by another, more understandable or analysable system.

Numerical analysis is the study of algorithms that use numerical approximation (as opposed to general symbolic manipulations) for the problems of continuous mathematics (as distinguished from discrete mathematics).

Point is, the usage of the term analog in this thread's context was simply meant to contrast the term digital. That's all (call the dictionary police) . . . what would terminology would you rather use?

 

[The Chairman]

Wow... you still haven't won your point. I've seen bulldogs give up a fight quicker. Analog is not the antithesis of digital. If you are going for analogous, then both PDCs and tables operate in the same manner.

 

[Huntingbigun]

Compare it to the flying world, the same thing comes along why have to learn the old ways of navigation when everyone has a Gps map, well be at 5000 feet over solid cloud cover and loose electrical power and you wish that you could read that map that your required to have.

Same for diving lots folks own their own boat and do not have a DM to plan for them, then in cave and all that fancy computer quits all have the same ending, whip out your trusty tables and your home free. I had many a trip on my boat or in a cave when my computers go oops nice to have a backup.

I love seeing ow newbies that have the cheapest bc, Walmart mask & reg setup but man they got that $1,000.00 wrist computer, :cool2:

Have fun here something new to chew on

 

[Kingpatzer]

Analogical models are a method of representing a phenomenon of the world, often called the ‘target system’ by another, more understandable or analysable system.

This is precisely what I"m talking about. I'm pretty sure no one is calculating dive tables using hydrodynamic flow meters, or some such. A mathematical model isn't an Analogical model unless it is using a source system to emulate a target. Again, that is not the case here. Tissue compartments, half-life and all the rest are theoretical abstractions, just as the resulting pressure groups are. There is no analogical system involved.

Numerical analysis is the study of algorithms that use numerical approximation (as opposed to general symbolic manipulations) for the problems of continuous mathematics (as distinguished from discrete mathematics).

Again, so what?

I know what the terms mean. I've spent enough time doing mathematics between my degrees and my job that I'm pretty sure I get the terms.

What's your point??

Most any discrete equation can be represented by a continuous function - and vice-versa. The one's that can not be so represented are not under discussion here.

Point is, the usage of the term analog in this thread's context was simply meant to contrast the term digital. That's all (call the dictionary police) . . . what would terminology would you rather use?

Some options:

RDP, Dive Planning Table, Decompression Table, Dive Table.

Compared to:

Computer. personal dive computer, dive computer.

The notion that "digital" is an issue demonstrates a focus that really has nothing to do with the question of to what degree do students need to understand tables in order to understand decompression theory (if at all), and should we be teaching dive planning using tables, computers or both?

You could build an analog computing system that could be used while diving which functioned as an analogical model for a digital dive computer and would output exactly the same information.

Why in the heck you'd want to engineer such a beast given the total lack of practical utility it would have aside, it wouldn't change the discussion. Conversely it is highly unlikely that any dive table a person would buy in the store today, or download from the net, is going to have been compiled without the use of a computer - which by necessity must model continuous functions as discrete mathematical operations.

So, here's my questions:

1) do you believe an analog widget is inherently superior to a digital widget?
2) do you believe that a dive table has a higher level of precision than a PDC?
3) do you believe that because a PDC is digital that it is prone to a higher failure rate than an analog pressure gage and a mechanical or digital underwater bottom timer?
4) do you believe that the differentiation between discrete and continuous mathematical functions is in any way relevant to the validity or utility of computations around decompression models for diving?

 

[The Chairman]

Compare it to the flying world, the same thing comes along why have to learn the old ways of navigation when everyone has a Gps map, well be at 5000 feet over solid cloud cover and loose electrical power and you wish that you could read that map that your required to have.

I think the real problem is that he has confused an analog depth gauge with tables and has combined the two. However, he's not about to concede defeat even when he is totally wrong.

Anolog Guage

Digital Guage​

 

[Kingpatzer]

Same for diving lots folks own their own boat and do not have a DM to plan for them, then in cave and all that fancy computer quits all have the same ending, whip out your trusty tables and your home free. I had many a trip on my boat or in a cave when my computers go oops nice to have a backup.

Yes, older dive computers had problems with reliability, we're not talking about diving with unreliable gear. Presently the mean time to failure for a dive computer is not significantly different than for a bottom timer. If you're adding in a depth gage, the computer is going to have a higher reliability because of the combined probability that either the gage or the timer might fail.

 

[Kevrumbo]

My points, Kingpatzer:

The basic digital calculator is a convenience but should never precede or replace fundamental knowledge & comprehension of analog four-operator arithmetic by hand.

The basic personal dive computer (PDC) is a convenience but should not precede or replace fundamental knowledge & comprehension of analog dive tables.

The 120 rule that you can use & generate "on-the-fly" is actually an applied analog heuristic algorithm & mnemonic taken from the old NAUI (and US Navy) NDL Air Dive Table.

. . .

Number Theory is to elementary arithmetic just as Decompression Theory is to dive tables.

The foundation and greater utility is first learning & comprehending elementary arithmetic, while the greater abstraction is going further to study & apply Number Theory, just as:

The foundation and greater utility is first learning & comprehending basic dive table decompression planning, while the greater abstraction is going further to study & apply Decompression Theory.

Electronic Digital Calculators/Computers are useful conveniences that should never precede or substitute for the learning of the fundamental elementary principles above. . .

Same further motivation as before. . .
http://www.scubaboard.com/forums/5268132-post59.html

To reiterate succinctly IMHO,

Classic analog tables will always serve you.
Digital electronic dive computers while desirable & convenient
will just serve you until the battery needs a recharge or replacement (or the unit malfunctions).

classic analog tables => generated by continuous function algorithm, uses base 10 elementary arithmetic evaluations where needed (i.e. RNT calculations etc);

digital electronic computer => fast & efficient, uses binary logic for symbolic evaluation & data storage by discrete mathematical operations.]

_____________________________

This is precisely what I"m talking about. I'm pretty sure no one is calculating dive tables using hydrodynamic flow meters, or some such. A mathematical model isn't an Analogical model unless it is using a source system to emulate a target. Again, that is not the case here. Tissue compartments, half-life and all the rest are theoretical abstractions, just as the resulting pressure groups are. There is no analogical system involved.

Again, so what?

I know what the terms mean. I've spent enough time doing mathematics between my degrees and my job that I'm pretty sure I get the terms.

What's your point??

Most any discrete equation can be represented by a continuous function - and vice-versa. The one's that can not be so represented are not under discussion here.

Some options:

RDP, Dive Planning Table, Decompression Table, Dive Table.

Compared to:

Computer. personal dive computer, dive computer.

The notion that "digital" is an issue demonstrates a focus that really has nothing to do with the question of to what degree do students need to understand tables in order to understand decompression theory (if at all), and should we be teaching dive planning using tables, computers or both?

You could build an analog computing system that could be used while diving which functioned as an analogical model for a digital dive computer and would output exactly the same information.

Why in the heck you'd want to engineer such a beast given the total lack of practical utility it would have aside, it wouldn't change the discussion. Conversely it is highly unlikely that any dive table a person would buy in the store today, or download from the net, is going to have been compiled without the use of a computer - which by necessity must model continuous functions as discrete mathematical operations.

So, here's my questions:

1) do you believe an analog widget is inherently superior to a digital widget?
2) do you believe that a dive table has a higher level of precision than a PDC?
3) do you believe that because a PDC is digital that it is prone to a higher failure rate than an analog pressure gage and a mechanical or digital underwater bottom timer?
4) do you believe that the differentiation between discrete and continuous mathematical functions is in any way relevant to the validity or utility of computations around decompression models for diving?

Tissue compartments, half-life and all the rest are theoretical abstractions, just as the resulting pressure groups are ---but the motivation is an analog application and analysis, however crude and inaccurate it may be, approximating decompression physics in human physiology. In that loose spirit, I choose to use the term analog vis-a-vis digital (and I really don't care whether you or NetDoc respect that tangent usage or not).

I don't understand how you abstracted this irrelevant line of questions from my points above, which have to do with education & learning of primary fundamental first principles versus the usage of electronic conveniences. . .

 

[The Chairman]

however crude and inaccurate it may be, approximating decompression physics in human physiology. In that loose spirit, I choose to use the term analog vis-a-vis digital (and I really don't care whether you or NetDoc respect that tangent usage or not).

Translation: I refuse to admit I was mistaken no matter how obvious it is.

I don't understand how you abstracted this irrelevant line of questions from my points above, which have to do with education & learning of primary fundamental first principles versus the usage of electronic conveniences. . .

I called you on your shenanigans and you refused to admit fault, committing more shenanigans. INSTEAD, you have endeavored quite unsuccessfully to prove that white is black and that up is down.

 

[Blackwood]

I don't understand how you abstracted this irrelevant line of questions from my points above, which have to do with education & learning of primary fundamental first principles versus the usage of electronic conveniences. . .

As a non-educator and non-instructor, I believe I would have more success teaching practical decompression theory using a PDC than using a table.

A computer in planning mode can show exactly that which a dive table displays, i.e. NDL decreases as depth increases, pressure group increases as dive time and depth increase, pressure group decreases as surface interval increases.

However, consider that few people actually dive square profiles. One would be hard pressed to show someone how multi-level profiles affect inert gas loading using a square-profile table. With a computer, I could show NDL, show the remaining NDL time decrease as bottom time increases, show what surface intervals do to repet NDL, AND I could show that remaining NDL time increases as the diver ascends to a shallower level.

In summary, it is my opinion that one can more readily impart useful information about decompression theory by using a computer or multi-level software (or wheel or RDPML) than by using the standard tables.

Everything that can be illustrated with a table can be illustrated with a PDC. The opposite is not true.

 

[Atom]

classic analog tables => generated by continuous function algorithm, uses base 10 elementary arithmetic evaluations where needed (i.e. RNT calculations etc);

digital electronic computer => fast & efficient, uses binary logic for symbolic evaluation & data storage by discrete mathematical operations.]

Since most tables are generated using computers and an algorithm I fail to see how tables are somewhat more "analog". You're just excuting the last part of the algorithm yourself...

They aren't really more continous than computers (you use a lot of quantization when you're using them, but it's safe). And whatever arithmetic base you use (2, 10, 13, whatever...) results are the same, only the digits changes.

But they do allow you to run a lot more "what-ifs" scenarios than most computers (at least the ones I've used), I find the innability of computers to give me some basic info I could get with a table somewhat irritating. For example, answering the question how much time do I have to wait before I can go down to y feets for x minutes is something I haven't seen integrated in the UI of most dive computers.