>= Nano Trivia <= , or is it?

[G Gabriel]

What is wrong with this picture?

something>=something_else
Or
something<=something_else

[Tom Cone Jr]

Re: &gt;= Nano Trivia &lt;= , or is it?

something will always be less then, equal to, or greater than something_else

the "picture" can't be used to define a subset of all possible values, since it will always be true

[G Gabriel]

Re: &gt;= Nano Trivia &lt;= , or is it?

Tom:
The point of my question is the implementation of the combined operands ">=" and "<=".

Are you OK with these?

[Tom Cone Jr]

Re: &gt;= Nano Trivia &lt;= , or is it?

G,

I think so. What am I missing?

[G Gabriel]

Re: &gt;= Nano Trivia &lt;= , or is it?

You are not missing much really. I see people do this all the time, using >= or <= not just in alpha but everywhere else. It's something that must have been around since the ice age, everyone is guilty of using it, myself (in the past) included. It's a mystery to me that even mathematicians use them. It's one of those mysteries like many of those black holes that live in my head and which I have yet to get my head around.

Let's say you have a filter that says:
filter="field >= 10"
That's the part I don't quite get!
Why ">="?
Wouldn't a better filter be:
filter="filed>9"

You might say, what's the big difference?
Maybe nothing, or maybe something, and something big.
In the first scenario, though I can't swear to it but, alpha will have to test for 2 conditions:
a-Whether the value is More than the field's value, and
b-If it is equal to it.

In the second scenario, alpha only test for one condition.

Ok... before somebody jumps in and says that there are situations where you HAVE to use the combined operand..I haven't found one yet.

[Tbaker]

Re: &gt;= Nano Trivia &lt;= , or is it?

Gabe

What if you were working on a calibration program of some sort where you would have to adjust pressures if the pressue was greater than or equal to 10

If you used the equation pressure >9 and then the function kicked in to adjust the pressure - if it reached 9.1 then the routine would execute but you were not supposed to adjust the pressure unless the pressure was greater than or equal to 10.

In that scenario (far out to say the least) you would need the equation >=10 not just >9 to accomplish what was needed.

Just my two cents worth.

Tom Baker

[G Gabriel]

Re: &gt;= Nano Trivia &lt;= , or is it?

In that scenario (far out to say the least) you would need the equation >=10 not just >9 to accomplish what was needed.

You only need one increment (whatever the increment you use in the particular scenario, said increment one more of which will make it 10). In a scenario like this, you would say:
pressure>9.99999 or whatever the increment might be.

[aRob]

Re: &gt;= Nano Trivia &lt;= , or is it?

This construct comes from mathematics where you deal with 'real' numbers, which can potentially have an infinite number of decimal places.

You only need one increment (whatever the increment you use in the particular scenario, said increment one more of which will make it 10). In a scenario like this, you would say:
pressure>9.99999 or whatever the increment might be.

If your 'scenario' changes slightly, then you need to go through the entire program looking for potential problems. All because you introduced a random constant ( 9 or 9.99999).

What about comparisons of variables where you want a>=b for numbers or strings?

[G Gabriel]

Re: &gt;= Nano Trivia &lt;= , or is it?

This construct comes from mathematics where you deal with 'real' numbers, which can potentially have an infinite number of decimal places.

And what expression do you have by way of example that uses an "infinite" decimal?
For alpha, or any software for that matter, to determine that one number is bigger than another it DOES NOT use an infinite number of decimals. Alpha is limited to 19 digits in numeric fields, Excel is limited to 39 I believe or something along these lines.

What about comparisons of variables where you want a>=b for numbers or strings?

Numbers mentioned above.
Characters might sound like it defies this logic, but not really.
I thought someone might take me up on this saying:
What if the base number is zero in a numeric evaluation or "a" in character evaluation?
Doesn't matter really, once again you go one increment less than the base number. If it is zero, then you say: field>-.1 or whatever the increment is. But what if it is "a"? what's one increment less than "a"?
Hmmm?
null.

Or based on the context, could be one ASCI lower.

The point of all of this is, the concept of "less than or equal to" and "more than or equal to" is somewhat of an urban legend that people take for face value without questioning.

OK..
Before someone asks the question: if null is less than "a", what then is more than "z"?
I am going to let you answer that.

Or
How do you construct something like: <="z"?
Yeh..
You will figure this one out too.

[Tbaker]

Re: &gt;= Nano Trivia &lt;= , or is it?

"zz" is greater than "z"

if using the equal sign "=" and not the exactly equal sign "==" the capital letter Z would be equal to z

Any other character than "z" or "Z" would show as less than "z"

[MikeC]

Re: &gt;= Nano Trivia &lt;= , or is it?

G,

And what expression do you have by way of example that uses an "infinite" decimal?

PI

[G Gabriel]

Re: &gt;= Nano Trivia &lt;= , or is it?

G,
PI

You really don't have to go to PI, you could produce an infinite number much easier but the question is, how do you compare two numbers (whether it is more, less or equal to the other) when either one or both are infinite?

You will be sitting doing this Ad infinitum, pardon the pun!
Hence and therefore mathematicians concluded that numbers produced by such thing as PI are "Irrational" or "Ttranscendental" and therefore the only way to use such number in a mathematical operation is by approximation. You can't possibly write a number with infinite decimals. There simply is not enough paper nor trees to accommodate your quest and in the computer world, there is no field big enough for infinity and at some point in time you are forced to say, I will approximate it after 10 or 20 or 30 decimals or whatever the case might be.

All that said, and if you still believe that you have to use ">=" or ", how are you going to use that with PI?
Are you going to say >=PI?
OK.. How is alpha to determine if the value in question is more than PI which has an infinite number of decimals?
Same dilemma, isn't?

[csda1]

Re: &gt;= Nano Trivia &lt;= , or is it?

In the first scenario, though I can't swear to it but, alpha will have to test for 2 conditions:
a-Whether the value is More than the field's value, and
b-If it is equal to it.

Alpha does not have to do two condition checks. On all modern CPU's and certainly the x86 family and 68k family of microprocessors, and comparison operation sets equality and sign flag values at the same time, allowing differentiation of any of the following <, >, <=, >=, =. <> in one conditional instruction. There is no speed penalty.

But x >= 10 is much more humanly understandable than x > 9.99999999999999 (whatever the maximum decimals are for the system). Since there is no penalty in speed, one should always use the most understandable syntax.

Character string comparisons are based on comparing characters from the left until the value differs or the end of the strings. == does a comparison of both length and case sensitive values. = normally compares case insensitive values, and stops when the operand on 1 of the sides ends if one is longer. (I forget which side it is for Alpha)

[Tbaker]

Re: &gt;= Nano Trivia &lt;= , or is it?

Mathematicians for centuries have used inequality symbols "< >" to compare one equation to another. They are a way of determining which avenue to pursue in the quest for a solution.

I would have to say, your post has been thought provoking but nonetheless, there will still be a need (be it a superficial one) to use greater than or equal to - less than of equal to in writing code where the user is in control of the input not the writer of the code.

In dates for example, given two dates to select records - it is easier for both the writer of the code and the user of the code to be able to write two dates without thinking about the inner workings of the code.

If I want a report to produce records between 02/15/09 and 5/15/09, in your way of thinking I would have to give the filter 02/14/09 and 05/16/09 to get the records from 02/15/09 to 05/15/09. I would think this would be too much to ask for our end users - it would cause brain spasms since we look at that equation as starting at the 15 of February and ending the 15 of May - not one day earlier and one day later.

So what I am saying, is that the developer is making it easier for the end user to perform his/her everyday tasks without much thinking other than what we use in the everyday world.

If we are talking about the great theorems of mathematics then the "greater than equal to" or "less than or equal to" is meant for greater minds than the everyday individual (me included) to think about.

I used to think that I had a pretty good grasp on everyday mathematics until my daughter went to college and majored in mathematics. - we did not speak the same language when it came to numbers.

Through alpha we are here to produce a product, an application and a solution for the end users. There are still many theorems in mathematics which have not been proven I would say - and there are others that are based on something that cannot be proven with current technology but are used.

I will say that in the 12 posts that this thread has produced - "My Brain hurts":D

G. it is always a pleasure reading your posts.

Tom Baker

[G Gabriel]

Re: &gt;= Nano Trivia &lt;= , or is it?

Tom:
I never expected anyone to change their way of thinking nor start doing things differently. Just sometimes I see things that are taken for granted that make no sense to me and creates a black hole in my brain and have to just say something about it. This is one of those. Don't get me started on Einstein black hole theory or theory of General Relativity. I read that darn thing and read more and came to the conclusion that Einstein was correct in his calculations but WRONG in his conclusion. But who the heck am I to question Einstein? Well, come to find out and as I read more about it, Einstein himself in his latte days questioned his own theory!

More than or equal to and its sister less than or equal to make absolutely no logical sense to me, none whatsoever.
And as far as the end user is concerned and the ease and convention of use, I would let them use what they are used to use then I convert it behind the scene. But once again, I titled my thread "Nano Trivia". It's just that, but worth looking into.