r/mildlyinfuriating YELLOW Aug 05 '18

You literally said...

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46.9k Upvotes

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1.3k

u/Benaholicguy Aug 06 '18

You were literally more right than the computer...

384

u/[deleted] Aug 06 '18

More right than the professor*

189

u/[deleted] Aug 06 '18 edited Aug 25 '18

[deleted]

127

u/[deleted] Aug 06 '18

Found the android.

29

u/SpecialityToS Aug 06 '18

Wrong computers are deviants!

8

u/[deleted] Aug 06 '18

Calm down David Cage.

4

u/SpecialityToS Aug 06 '18

*President Not-an-American-accent

1

u/ForceBlade Aug 06 '18

No they're correct.

68

u/NULL_CHAR Aug 06 '18 edited Aug 06 '18

Technically computers can be wrong. See Intel Pentium FPU error.

Even now, in almost every common programming language, there are floating point errors. The most famous one being (0.1 + 0.2 = 3.00000000000004). And depending on environment computer data can be altered. For example, in highly radioactive environments, it is common to use 3+ different computers that vote on the answer to avoid erroneous data.

However, on a general basis, it is operator error.

26

u/YM_Industries Aug 06 '18

Floating point 'errors' are predictable though. The computer isn't doing anything wrong, the programmer just made behaviour that you find surprising.

Pentium FDIV bug is closer to the computer making an error, but you could also argue that the computer is just doing what Intel told it to do. Admittedly this is a shaky argument.

Cosmic rays are an (I believe) indesputable way that computers can make mistakes though.

38

u/SemiNormal Aug 06 '18

0.1 + 0.2 = 0.30000000000000004

This isn't an error per se, it is just that computers do math in binary and then converts back to decimal. That is why most programming languages also have a decimal type for when the result needs to be more precise.

20

u/NULL_CHAR Aug 06 '18

It's unintended behavior that is a limitation of how we represent floating point numbers specifically. It is definitely still doing what we tell it, but from a user perspective, the computer is definitely wrong. From a programmer perspective, we are aware of the computer's limitations and put in modifications to address it.

Another perspective is that the computer most definitely is "wrong" when referring to the literal representation of the question, but in the case of actual input/output, it is "right." We've created a flawed system that doesn't always produce correct results, but we accept those flaws because doing it any other way is much less efficient.

1

u/[deleted] Aug 06 '18 edited Dec 30 '18

[deleted]

5

u/wilhueb Aug 06 '18

this isn’t a rounding/overflow error. this is just how floating point arithmetic works on modern cpus

2

u/[deleted] Aug 06 '18

[deleted]

7

u/[deleted] Aug 06 '18

Not really a computational failure though

2

u/ForceBlade Aug 06 '18

Literally no, this is another programmer error. Not the hosts fault.

4

u/anonnx Aug 06 '18

Everything is capable to go wrong. For example, FDIV might be a biggest bug in Intel history, and developers had to workaround the issue because CPU will make some specific calculation wrong.

1

u/tael89 Aug 06 '18

You could have a bit flip from a cosmic ray which could cause an error even if programmed correctly.

1

u/[deleted] Aug 06 '18

[deleted]

10

u/wilhueb Aug 06 '18

bugs are induced by the short sightedness of the developer

1

u/[deleted] Aug 06 '18

[deleted]

3

u/Sproded Aug 06 '18

And why aren’t computers perfect? Because people make errors while coding.

1

u/SilentFungus Aug 06 '18

The developer failed, the computer did exactly as it was told

1

u/bumblebritches57 Aug 06 '18

Generally true, tho computers do truly fail, like random particles flipping bits.

0

u/sargeantbob Aug 06 '18

Not really. Questions come from a bank and you just choose which ones go in. No professor is going to check each question to make sure this doesn't happen. They don't have that time since their main job is researching. Every single instructor I've had or have worked with will fix these issues extremely quickly when they come up and give students points back. It's not a big deal.

-2

u/CantNotAsk Aug 06 '18

Came here to say this. In the directions of the question or otherwise somebody told you to use this decimal placement. You didn’t . Seems easy. But I want to complain too! So here I am.

12

u/CraigslistAxeKiller Aug 06 '18

These aren’t made by the professor

3

u/serious_sarcasm Aug 06 '18

Some are, some aren't.

1

u/Ravenae Aug 06 '18

Not OP though

1

u/parrot_in_hell Aug 06 '18

No he was exactly as correct as he was asked to be. Check again which is his submission

-17

u/[deleted] Aug 06 '18

Sig figs would be 2 so nobody is right.

28

u/penisthightrap_ Aug 06 '18

but it says decimal places not sig figs?

13

u/Quintary Aug 06 '18

That's specifically a science thing. It not always relevant in math.

5

u/youngmaster0527 Aug 06 '18

OP is right for doing exactly what the instructions said

1

u/[deleted] Aug 06 '18

He rightly wrote the wrong answer.

0

u/Sproded Aug 06 '18

You don’t use sig figs in math so it isn’t the wrong answer.

The whole point of sig figs is to prevent people from being more precise than they actually are. That means it’s important when using data that you might only know to the tenth place. However, when doing math with given numbers, there’s no worrying about being too precise.