The Daily WTF: Curious Perversions in Information Technology

Nagesh · 2012-07-09 Reply Admin

pjt33:
Jay:
Indeed, when I took chemistry in college, we had a question on a test that said you have a beaker with 40 g of water, you add .01 g of salt, what is the weight of the resultant mixture? The correct answer was 40 g.
That's how you know it was a chemistry question. If it had been a physics question the correct answer would have been 0.4N (assuming it to be in close proximity to the surface of the Earth).

Are not good scales available in your country?

2012-07-09 Reply Admin

That second explanation makes sense. Also, if you want to make fun of people who literally interpret the bible there are lots of other examples that could have been chosen that wouldn't also have made you look like an idiot.

2012-07-09 Reply Admin

Oh, yay, this argument again. Okay, let's run with this.

So you're saying that 1 Kings 7 is an engineering document, and as such only needs to be accurate to within the engineering tolerances of Solomon's temple. Hey, I'll buy that. The whole chapter is discussing the dimensions of the building in detail. I guess that means the temple, then, was built to a tolerance of 1.4 cubits, or about one meter.

Meanwhile, contemporary construction by the Egyptians was built to tolerances lower than a couple millimeters (the thickness of a sheet of papyrus, anyway). Perhaps that's why the Pyramids of Giza are still standing and Solomon's Temple, well, isn't.

As an engineer myself, maybe I should be praying to Ra and Anubis, instead.

2012-07-09 Reply Admin

Nagesh:
pjt33:
Jay:
Indeed, when I took chemistry in college, we had a question on a test that said you have a beaker with 40 g of water, you add .01 g of salt, what is the weight of the resultant mixture? The correct answer was 40 g.
That's how you know it was a chemistry question. If it had been a physics question the correct answer would have been 0.4N (assuming it to be in close proximity to the surface of the Earth).

Are not good scales available in your country?

Yes

2012-07-09 Reply Admin

Infinite Time and Space:
operagost:
Even if we ignore the definition of the word "miracle", there are plausible circumstances in which a person could walk (or appear to walk) on water. But pi is a constant that will never be 3.

I disagree. Perhaps PI is not really constant throughout all time and positions in the infinite universe? Perhaps it is changing ever so slightly, so slow that in all of human history and in our galaxy, the change would be undetectable. At some point in time and space, it very well could be 3.

You are confusing physical constants - such as the speed of light- which theoretically could change, with mathematical constants - such as pi - which are completely independent from the universe. Pi cannot change.

2012-07-09 Reply Admin

Heinz:

You can get this code to fail:

/**
 * Tests if {@link XXXX} class extends {@link Object} class.
 */
@Test
public void testInheritance() {
    Assert.assertTrue("Class does not extends Object class.",
        instance instanceof Object);
}

Simply pass in "null".

That's not inheritance; that's instantiation. So the WTF stands.

2012-07-09 Reply Admin

Boolean is missing the south jersey "yeh" and "nawh"

2012-07-09 Reply Admin

pjt33:
Jay:
Indeed, when I took chemistry in college, we had a question on a test that said you have a beaker with 40 g of water, you add .01 g of salt, what is the weight of the resultant mixture? The correct answer was 40 g.
That's how you know it was a chemistry question. If it had been a physics question the correct answer would have been 0.4N (assuming it to be in close proximity to the surface of the Earth).

If an atomic physicist had answered it, the answer would be given in electron-volts. Still don't understand those buggers (the measurement and those people).

2012-07-09 Reply Admin

Infinite Time and Space:

I disagree. Perhaps PI is not really constant throughout all time and positions in the infinite universe? Perhaps it is changing ever so slightly, so slow that in all of human history and in our galaxy, the change would be undetectable. At some point in time and space, it very well could be 3.

Bzzt! Try again.

PI is a mathematical constant. It's not a physical property of the universe. It's like saying that 1 + 1 might equal 3 in the future.

2012-07-09 Reply Admin

public static int getNegativeOfNumber ( int num )

{ if (num > 0) {return -1*num} else {return num} }

2012-07-09 Reply Admin

Ninkasi:
Oh, yay, this argument again. Okay, let's run with this.
So you're saying that 1 Kings 7 is an engineering document, and as such only needs to be accurate to within the engineering tolerances of Solomon's temple. Hey, I'll buy that. The whole chapter is discussing the dimensions of the building in detail. I guess that means the temple, then, was built to a tolerance of 1.4 cubits, or about one meter.

Meanwhile, contemporary construction by the Egyptians was built to tolerances lower than a couple millimeters (the thickness of a sheet of papyrus, anyway). Perhaps that's why the Pyramids of Giza are still standing and Solomon's Temple, well, isn't.

As an engineer myself, maybe I should be praying to Ra and Anubis, instead.

Or we can assume that the dude writing the passage was a scribe and not a fucking engineer - therefore making any inaccuracies in reporting the measurement hardly surprising or noteworthy.

2012-07-09 Reply Admin

null:
public static int getNegativeOfNumber ( int num )
{ if (num > 0) {return -1*num} else {return num} }

U ain't remembering to put in semi-colons.

2012-07-09 Reply Admin

Also

Nagesh:
null:
public static int getNegativeOfNumber ( int num ) { return num > 0 ? num * -1 : num; }
U ain't remembering to put in semi-colons.

2012-07-09 Reply Admin

If you draw a line segment from the center of a unit circle to some point on the circle at theta degrees, and then draw a right triangle to show the rise and run of that segment, cosine is the run and sine is the rise, and tangent is the slope, slope being rise / run, tan is sine / cosine.

Since 360 degrees = 2pi radians, 45 degrees is pi/4 radians, and a line at 45 degrees has a slope of 1. So tan(pi/4) = 1, solving for pi we get:

pi = 4 * arctan(1)

That's usually the best way to get pi if you have the relatively common arctan function. It's also a good way to test if your trig functions are broken...

emurphy · 2012-07-09 Reply Admin

Kaniu:
Round isn't actually that bad. It's a way to replace C#'s default rounding "half towards even" with a more conventional "half towards up".
The real WTF is why would anyone want to use banker's rounding as a default method. http://msdn.microsoft.com/en-us/library/aa340227(v=vs.71).aspx http://en.wikipedia.org/wiki/Rounding#Round_half_to_even

Because the industry standard has said so for upwards of 25 years? http://en.wikipedia.org/wiki/IEEE_floating_point#Rounding_rules

Of course, industry standards can be WTFs too, but this one makes sense because the sum of rounded figures (assuming they're fairly evenly distributed) is closer to the sum of unrounded figures.

Simple example: You need to output 10,000 positive dollar amounts, which for whatever reason need to be individually rounded to the nearest dollar. 500 of them are $(something).50, of which 256 of them are $12.50 and 244 of them are $11.50 (so the sum of those 500 transactions without rounding is $6,006).

If you use round-half-toward-even, then you end up with $6,000. If you use round-half-up, then you end up with $6,500.

In theory, you could hit $6,006 exactly by going back and arbitrarily selecting 6 of the $12.50 amounts to round up, but that's usually considered more trouble than it's worth. (I did have at least one project where the client wanted to hit the target exactly; I ended up arbitrarily selecting the last transaction and fudging it by whatever amount it took, which the client considered acceptable.)

D-Coder · 2012-07-09 Reply Admin

Sayer:
Ninkasi:
Oh, yay, this argument again. Okay, let's run with this.
So you're saying that 1 Kings 7 is an engineering document, and as such only needs to be accurate to within the engineering tolerances of Solomon's temple. Hey, I'll buy that. The whole chapter is discussing the dimensions of the building in detail. I guess that means the temple, then, was built to a tolerance of 1.4 cubits, or about one meter.

Meanwhile, contemporary construction by the Egyptians was built to tolerances lower than a couple millimeters (the thickness of a sheet of papyrus, anyway). Perhaps that's why the Pyramids of Giza are still standing and Solomon's Temple, well, isn't.

As an engineer myself, maybe I should be praying to Ra and Anubis, instead.

Or we can assume that the dude writing the passage was a scribe and not a fucking engineer - therefore making any inaccuracies in reporting the measurement hardly surprising or noteworthy.

Of course. Unless the base assumption is that the Bible is literally true. In which case you're a heretic.

Oh and let me be the first to point out that this is not the Christian bible, but the Hebrew bible, and you may send my pedantry points to me at your convenience.

KattMan · 2012-07-09 Reply Admin

Sayer:
Ninkasi:
Oh, yay, this argument again. Okay, let's run with this.
So you're saying that 1 Kings 7 is an engineering document, and as such only needs to be accurate to within the engineering tolerances of Solomon's temple. Hey, I'll buy that. The whole chapter is discussing the dimensions of the building in detail. I guess that means the temple, then, was built to a tolerance of 1.4 cubits, or about one meter.

Meanwhile, contemporary construction by the Egyptians was built to tolerances lower than a couple millimeters (the thickness of a sheet of papyrus, anyway). Perhaps that's why the Pyramids of Giza are still standing and Solomon's Temple, well, isn't.

As an engineer myself, maybe I should be praying to Ra and Anubis, instead.

Or we can assume that the dude writing the passage was a scribe and not a fucking engineer - therefore making any inaccuracies in reporting the measurement hardly surprising or noteworthy.

And my troll post is still winning. And yes this is a good way to show that the bible was written by man and not God. It's a history book written by religious people, the events did happen as they see it, but the interpretation is left up to the reader, hence why faith is important.

2012-07-09 Reply Admin

Any real computer or maths buff should know Pi is roughly 3.14159265358979323846264338327950288419716939937510582097494492307. Come on, is it really that hard to remember?

2012-07-09 Reply Admin

Canada Eh?:
I walk on water all the time. From late December to about March.

Make up your mind.

2012-07-09 Reply Admin

jaloopauser="Paul Carter"][quote user="Infinite Time and Space"]

I disagree. Perhaps PI is not really constant throughout all time and positions in the infinite universe? Perhaps it is changing ever so slightly, so slow that in all of human history and in our galaxy, the change would be undetectable. At some point in time and space, it very well could be 3.[/quote]

Bzzt! Try again.

PI is a mathematical constant. It's not a physical property of the universe. It's like saying that 1 + 1 might equal 3 in the future.[/quote]

Actually, if you define pi as the ratio of a circle's radius and circumference then it only equals the commonly accepted value in Euclidean flat space. In a curved spacetime it is different

2012-07-09 Reply Admin

Jay:
Apparently Moses understood science better than you do.

Are you saying Moses wrote that part?

2012-07-09 Reply Admin

[quote user="Paul Carter"][quote user="Infinite Time and Space"]PI is a mathematical constant. It's not a physical property of the universe. It's like saying that 1 + 1 might equal 3 in the future.[/quote]

Only if you assume flat spacetime. One could easily construct a circle which has a measured ratio of circumference to diameter equal to exactly 3.00(bar) if one does so on an appropriately curved spacetime manifold. I leave proof-by-demonstration as an exercise for the student.

2012-07-09 Reply Admin

For the negative number problem, based on the code given, it sounds like the method is required to only output a negative number. So, I would think something like this would fulfill the requirement:

public double GetNegative(double given)
{
    if(given < 0) return given;

    return -1 * given;
}

I use multiplication, because in a conversation about this very WTF, I learned that there are cases where multiplication is actually faster than just 0-x!

CAPTCHA: jumentum - It's like Jumanji, with momentum!

2012-07-09 Reply Admin

pjt33:
That's how you know it was a chemistry question. If it had been a physics question the correct answer would have been 0.4N (assuming it to be in close proximity to the surface of the Earth).

N is a measure of force, the question was about weight. If you had been in a physics test you would have got that one wrong.

2012-07-09 Reply Admin

AGray:

public double GetNegative(double given)
{
    if(given < 0) return given;
return -1 * given;

}

Actually, I could've done it better:

return (given < 0) ? given : -1 * given;

I am the WTF! :O

2012-07-09 Reply Admin

Anketam:
The actual smallest unit of currency in the US is 1/10 of a cent. Just look at gas prices, they love charging 9/10 of a cent per gallon of gas.

This is TRWTF. When are gas stations going to drop the ridiculous 9/10 of a cent pricing scheme?

Back in 1950 you could fool people into thinking $.57 9/10 is 3 cents cheaper than $.60 because saving three dimes on your 20 gallon fill up meant something. But today it's going to take at least a two dime difference per gallon to get me to go across the street for some gas.

When there is a 3 or 4 or 5 on the left side of the decimal point, you need to drop the silly 9/10 of a cent charade.

2012-07-09 Reply Admin

There are an infinite number of possible systems of mathematical notation in which 22/7 is an exact representation of PI.

None of them, however, are in common use.

2012-07-09 Reply Admin

justsomedude:
pjt33:
That's how you know it was a chemistry question. If it had been a physics question the correct answer would have been 0.4N (assuming it to be in close proximity to the surface of the Earth).

N is a measure of force, the question was about weight. If you had been in a physics test you would have got that one wrong.

Weight is a force. Mass is not (in conventional sense).

TGV · 2012-07-09 Reply Admin

Sayer:
Or we can assume that the dude writing the passage was a scribe and not a fucking engineer - therefore making any inaccuracies in reporting the measurement hardly surprising or noteworthy.

Someone's getting upset and using ugly words that have been forbidden by his god, or rather, the people that claim to be the representatives of his deity of preference.

Sayer: you either take the Bible literally, or you don't. There is no FileNotFound option.

2012-07-09 Reply Admin

KattMan:
faith is TRWTF

FTFY

2012-07-09 Reply Admin

i really, really, REALLY hope Andy P doesn't work for NASA, any engineering firm, or any engineering software firm.

2012-07-09 Reply Admin

Paul Carter:
Infinite Time and Space:

I disagree. Perhaps PI is not really constant throughout all time and positions in the infinite universe? Perhaps it is changing ever so slightly, so slow that in all of human history and in our galaxy, the change would be undetectable. At some point in time and space, it very well could be 3.

Bzzt! Try again.

PI is a mathematical constant. It's not a physical property of the universe. It's like saying that 1 + 1 might equal 3 in the future.

1+1=3 is certainly true in a given magma (M,+) where the operator + is defined as +: a+b+1 for all a,b in M.

So no, it's not like saying that. The rest of your comment is correct.

2012-07-09 Reply Admin

const float tau = (44.0f/7);

There, fixed!

2012-07-09 Reply Admin

TGV:
Sayer: you either take the Bible literally, or you don't. There is no FileNotFound option.

I don't. You got a problem with that?

But even so, the literal meaning of "thirty cubits" is not "30.0 cubits exactly". None of the extant manuscript include the word "exactly" (or rather, any words in the original language, probably biblical Hebrew, that would support such a translation). There is no reason to exist any such manuscript ever existed.

Taking something "literally" includes, by definition, refraining from injecting any meaning into it that isn't there, such as your insistence on a spurious assumption of mathematical exactness.

2012-07-09 Reply Admin

Nagesh:

public static int getNegativeOfNumber ( int num ) 
{
   int absolueValue=Math.abs(num) ;
   int negativeInt=-1*absolueValue ;
   return negativeInt;
}

Remember: it is always praferrable to put the inside of the function in one line to spend less space and make the client happy:

public static int getNegativeOfNumber ( int num ) 
{
   return -1*Math.abs(num);
}

2012-07-09 Reply Admin

TGV:
Sayer: you either take the Bible literally, or you don't. There is no FileNotFound option.

I am not exactly a devout christian, but that's just false. There is no exact border that separates "literally" from "non-literally". Words are just pointers to fuzzy concepts, even without taking into account that they are stored inside brains and their values differ from person to person (apply that to both the word "literally" and the contents of the Bible).

2012-07-09 Reply Admin

Still ignoring positive and negative zero...

2012-07-09 Reply Admin

operagost:
Even if we ignore the definition of the word "miracle", there are plausible circumstances in which a person could walk (or appear to walk) on water.

I walked across the river Thames last week. Didn't even get wet.

Useful things, bridges.

2012-07-09 Reply Admin

I was expecting one of the first comments to be a "GRAVEYARD OF BAD COMMENTS" marker. I am greatly disappointed.

PiisAWheeL · 2012-07-09 Reply Admin

XXXXX:
Paul:
{"Maybe",__TIME__[7]&1}
C'mon, is this for real? I guess you gotta love a boolean that successfully implements Maybe.
Gentlemen, we are within inches of developing the technology to properly handle True, False, FileNotFound.

Never has a comment on this site been more FileNotFound. You should be AdjectiveNotFound of yourself.

Uhhh... Noun_not_found?

Anketam:
Some Damn Yank:
Anonymous Genius:
Yeah, apart from the missing '+' it seemed fairly reasonable to me. There are valid reasons for wanting to write your own rounding routine-- for example, in many financial applications, it is desirable to add something like 0.5000000001 instead of 0.5 to keep floating point error from causing the result of some calculations to round down erroneously.
You shouldn't use floating point for financial calculations. You always round to the nearest penny, in the [bank's|government's|company's] favor. In the case of the IRS, you round to the nearest dollar in the government's favor.
The actual smallest unit of currency in the US is 1/10 of a cent. Just look at gas prices, they love charging 9/10 of a cent per gallon of gas.

Actually, if you've ever purchased penny stocks, you can buy stock for .0001 Cents, or 1/100th of a penny.

Tristram:
Ooh, I know how to fix this code. Works as advertised:
// Convert to negative number

varInt := StrToInt('-1');

That fails on an input below 0.

2012-07-09 Reply Admin

Sucker you fell for a myth.

2012-07-09 Reply Admin

ShatteredArm:
{"Maybe",__TIME__[7]&1}
I see no problem with the computer making a decision for you if you're waffling. This is a solid implementation of "Maybe."

I agree, though I would personally prefer a solution that defines the uncertainty at run-time rather than compile-time.

2012-07-09 Reply Admin

operagost:
Even if we ignore the definition of the word "miracle", there are plausible circumstances in which a person could walk (or appear to walk) on water. But pi is a constant that will never be 3.

In Pinary, the value of pi is 1.0

2012-07-09 Reply Admin

Whosdr:
Any real computer or maths buff should know Pi is roughly 3.14159265358979323846264338327950288419716939937510582097494492307. Come on, is it really that hard to remember?

+1

2012-07-09 Reply Admin

Nagesh:
PZ:
22.0f/3 was quite a common way of representing PI in a rough way before frameworks came long and stuck 'official' PI constants in.

In the India we using 22/7, no 22/3.

Thank you, come again!

@PZ Why would people use 22/7 before any official 'PI' constant? When I was a wee tacker, we used to round to 3.142 and I'd be surprised if most people who have ever had to use PI for anything would probably use 3.142 or even better resolution (eg 3.14159). Given 22/7 (3.1428571....) rounds to 3.143 it's simply the wrong value to use....

And given that the more mathematical we geeks get the more pedantic about accuracy we are, I'm sure the peeps using Pi way back when would have preferred to explicitly use something like 3.141592653589793 (even though I'm near certain that would get truncated)

22/7 is fine for primary school kids who want to work out the perimeter of circle then measure it with a piece of string to see that it was correct, but I'm not sure it's even close to an adequate estimate of Pi for any other reason....

Maybe they should have had 21.99115848/7

2012-07-09 Reply Admin

KattMan:
Nagesh:
PZ:
22.0f/3 was quite a common way of representing PI in a rough way before frameworks came long and stuck 'official' PI constants in.

In the India we using 22/7, no 22/3.

Thank you, come again!

The Christian bible states that PI is 3. No floats needed back in those days I guess.

No it doesn't.

2012-07-09 Reply Admin

operagost:
Pastor Eyes:
KattMan:
Nagesh:
PZ:
22.0f/3 was quite a common way of representing PI in a rough way before frameworks came long and stuck 'official' PI constants in.

In the India we using 22/7, no 22/3.

Thank you, come again!

The Christian bible states that PI is 3. No floats needed back in those days I guess.
Well if you're going to pay any attention to that old thing, it also says Jesus walked on water. No floats needed for that either I suppose.
Even if we ignore the definition of the word "miracle", there are plausible circumstances in which a person could walk (or appear to walk) on water. But pi is a constant that will never be 3.

Ah yes.... The Mathematician says that PI is approximately: 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679 The Computer Scientist says that Pi is exactly 3.14 The Physicist says that pi is a number somewhere around 3 whose precise value is not important and can be calculated to whatever accuracy needed as needed, provided people understand why we use it in these claculations. The Baker is sick of Pi....

2012-07-09 Reply Admin

Jay:
KattMan:
The Christian bible states that PI is 3. No floats needed back in those days I guess.

At the risk of being mildly serious: The Bible gives the measurements of a certain object, mentioning that the diameter is 10 and the circumference is 30.

(a) There is no such thing as an "exact measurement"; there is only measurement within a certain precision. This is commonly discussed in science classes under the heading "significant figures" -- feel free to google the phrase for details. As the quote is not from a scientific treatise but from a general discussion of the furniture in a certain building, the writer does not tell us the number of significant digits, but it's likely 2 or maybe only 1 (given that both numbers are multiples of ten). If you perform an arithemtic calculation on two numbers and the least accurate has only one significant digit, the answer is only meaningful to one significant digit. If the writer had said that he measured the circumference as 10 cubits accurate to 1 significant digit, and then concluded that the circumference was 31.42 cubits, he would have been marked wrong in my chemistry and physics classes.

Indeed, when I took chemistry in college, we had a question on a test that said you have a beaker with 40 g of water, you add .01 g of salt, what is the weight of the resultant mixture? The correct answer was 40 g. Students who wrote 40.01 g were marked wrong, because they had failed to understand the concept of significant figures.

In this case, 10 * 3.14159... = 30 -- one significant digit -- not 31.4159. You can't invent additional precision out of thin air.

(b) Even ignoring that this is a physical measurement and therefore inherently an approximation, pretending it's a question in abstract geometry, please tell me what you think the "correct" answer is. If you say 31, you are no better than the original writer: pi is no more equal to 3.1 than it is to 3. If you say 31.4, that's not an exact value for pi either. You could give 100 digits and it still wouldn't be exact. No matter how many digits you give, you will not be stating the exact value for pi. The only way to exactly state the value of pi is to say "pi" or give an algorithm. I suppose the writer could have said that the circumference was "10 times pi", but that just leaves it to the reader to do the calculation himself.

So you're ridiculing the Bible for, (a) failing to ignore the concept of significant figures, and (b) failing to ignore the fact that pi is a transcendental number. Apparently Moses understood science better than you do.

I think the word pi was lost in translation because the non-aramaic speaking world didn't have a word for it yet...

Also, given they didn't have computers back then, let alone very accurate measuring devices, I think we can accept that 3 was about as accurate as Pi was going to get - but I guess this ties in with your rant about signifcant figures. Apparently Alan Turing was one of them....

2012-07-09 Reply Admin

Ninkasi:
Oh, yay, this argument again. Okay, let's run with this.
So you're saying that 1 Kings 7 is an engineering document, and as such only needs to be accurate to within the engineering tolerances of Solomon's temple. Hey, I'll buy that. The whole chapter is discussing the dimensions of the building in detail. I guess that means the temple, then, was built to a tolerance of 1.4 cubits, or about one meter.

Meanwhile, contemporary construction by the Egyptians was built to tolerances lower than a couple millimeters (the thickness of a sheet of papyrus, anyway). Perhaps that's why the Pyramids of Giza are still standing and Solomon's Temple, well, isn't.

As an engineer myself, maybe I should be praying to Ra and Anubis, instead.

I think I found your problem....

2012-07-09 Reply Admin

C-Derb:
Back in 1950 you could fool people into thinking $.57 9/10 is 3 cents cheaper than $.60 because saving three dimes on your 20 gallon fill up meant something. But today it's going to take at least a two dime difference per gallon to get me to go across the street for some gas.

Back in 1950, if you charged $0.579/gal you'd better be someplace like Death Valley or you'd be the laughingstock of the town. I was paying $0.199/gal in 1972. Then the Shaw needed money to buy weapons from the USA so Kissinger told him to charge more for oil and the rest is history, but I digress.

The Object Test, a New PI, and More SHEEIT

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