Understanding Floating Point Struggles in 7 Minutes or Less

Рет қаралды 9,643

5 ай бұрын

Ever wonder why weird things happen with floating point numbers? In this video I'll go throw why that is.
Decimal to binary video:
• How To Count in Binary...
Hope you enjoyed the video!
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Пікірлер: 37

@johnbarbero757 5 ай бұрын

There are definitely places in computer graphics where floating point errors will become noticeable (texture bleeding, or other weird lines/banding). I also ended up having to rip out float as the underlying datatype for a budgeting application I worked on since the errors were biting me in all kinds of unexpected places. Python has a Decimal type, which worked well for my use case as replacement.

@OddMathisen 5 ай бұрын

This is why floating point comparison is usually done with some threshold. I.e. to check if variable A is equal to 0.3, you would compare A-0.3

@ZacKoch 5 ай бұрын

Nice work. Coming from a networking background watching you explain how to represent 12 made me want to bang my head on my desk though. 😂 You're not wrong, but the way you explained it is like rocket science from how I've been doing it all my life lol. This may be the first time I can explain something to YOU in an easier way vs the other way around lol. ❤

@darrenphillips1845 5 ай бұрын

It's a wonder we didn't shoot right past the moon.

@zane812 5 ай бұрын

never went

@darrenphillips1845 5 ай бұрын

@zane812 - When they say we lost the 60s tech that we used to get to the moon, and that's why we haven't gone back, I'd tend to agree with you.

@nitsanbh 5 ай бұрын

@@zane812so during the Cold War, Russia joined the US lie (by not publishing the moon landing was faked)? That’s an even bigger conspiracy theory

@Chicken_Soy 5 ай бұрын

To the moon! 🚀 🌝 Playboi carti 2024 album upcoming

@baileyharrison1030 5 ай бұрын

@@darrenphillips1845We haven’t lost the tech we’ve lost the motivation and funding. Back then, the space program was 5% of the federal budget, now it’s 0.5%. People were complaining that the government ‘spent too much money on the moon’.

@JohnDoe4321 5 ай бұрын

One of the consequences of this is that you should avoid doing equality comparisons on floating point numbers. Code like "if (a + b + c == 1.0)" is subject to unexpected failure.

@bertblankenstein3738 5 ай бұрын

Exactly! It is OK to use 《 or 》but == should not occur. Perhaps check if a number is within a range as an alternative solution.

@paulm3702 5 ай бұрын

Great seeing a visual breakdown of the memory and the walkthrough for the problem!

@repairstudio4940 5 ай бұрын

I truly enjoy your videos. When will you do a video about yourself, an intro, how you got started developing? What's your favorite language? A Q&A stream would be cool...🎉

@mechjack 5 ай бұрын

I've seen math programs such as mathcad keep floating point numbers as fractions of whole numbers, i believe to fix this very problem .

@C4rb0neum 5 ай бұрын

Amazing quality video! It’s clear that you have skills

@ndbass09 5 ай бұрын

Love your videos. Keep it up!

@shadowpenguin3482 5 ай бұрын

5:00 I did not get that one. You just explained that the numbers are the same but have different exponents. That means even in binary 0.2 is exactly 2*0.1. So either they are both slightly larger than the decimal number or both slightly smaller.

@alankoester3344 5 ай бұрын

Something completely off topic. You had a video a year ago about the end of the Atom text editor. It seems it was revived as Pulsar IDE. Would you be interested in looking at it and report on it?

@nepp9574 5 ай бұрын

A different technique for converting decimal to binary is starting from the left to see if it fits in your number and then substracting that from your number if it does: 9 1000 ^^^^ 8421 9 - 8 = 1 1001 ^^^^ 8421 1 - 1 = 0 If this makes sense at all. Only requires you to know what the left most bit represents, which is 8 in this case.

@EngineerMan 5 ай бұрын

Yes so this was the way I taught it in my binary video in description.

@ecavero1 5 ай бұрын

0:51 If you use groovysh, 0.1 + 0.2 does give you 0.3, This is because Groovy uses Java's BigDecimal class by default.

@borstenpinsel 5 ай бұрын

Which doesn't rely on floating point precision and uses more memory than a single integer and more cpu time than a simple addition of 2 registers. You can calculate beyond the precision of a 64 bit float. (How else are computers coming up with the 1000th decimal place of Pi). It just uses more memory and flops

@KontrolStyle 5 ай бұрын

we love some engineer man 8)

@PrivateUsername 5 ай бұрын

Maybe add in a bit about ULP? That could help with understanding why you get .30000004 vs .30000012 or whatnot.

@MisterDan 24 күн бұрын

Very nice video BTW.

@esra_erimez 5 ай бұрын

Really good video. If you want a good treatment on floating point, I recommend one of my dad's favorites "Numbers in Theory and Practice" by Blaise W. Liffick. And, if you want a really in depth treatment on the subject, the authoritative source is Knuth's "Art of Computer Programming, The: Seminumerical Algorithms, Volume 2"

@lyshaka 5 ай бұрын

I just tried it in C just to see the result (which is obviously the same), but the error is definitely greater using simple float rather than double : float precision : float : 0.30000001192092896000 double : 0.30000000000000004000 using that code : #include int main(int argc, char **argv) { float f_res = 0.1 + 0.2; double d_res = 0.1 + 0.2; printf("float precision : "); printf("float : %1.20f ", f_res); printf("double : %1.20f ", d_res); return (0); }