"Temperature doesn't just go from hot to cold" Obviously you've never used a shower.

The temperature of this water is true.

Only A Sith Deals In Absolutes

I've tried many times to explain fuzzy logic to my (laymen) friends, ironically with varying degrees of success. I think from now on I'll refer them to this video. Well done, thanks.

I think this may have been better described with an example a bit more tangible, like colors. A good example of fuzzy logic is determining if a color is similar to another. First you break down into the three RGB values, then you have to make sure no individual color is too different by comparing the difference, then you have to take the total differences in all three colors and make sure IT is not too large. :)

So lots of people liked this video? But if all you can do is either Like or Dislike it, it isn't possible to tell just how well the video was liked. KZfaq's rated "quality" is a straight forward calculation: Rating = Likes / (Likes + Dislikes). What this doesn't tell us is "how much" someone liked or disliked it. If KZfaq used a star rating, where the viewer can select 5 stars for "great" and one star for "poor", fuzzy logic would be automatically inherent and a more accurate rating would be computed. Using a simple Like/Dislike rating system requires a lot of votes to give you an overall feel to how much a video is liked. I suspect that if a star rating were used, the bar graph showing how well this video is liked would be different. Humans shouldn't have to be forced to choose either Like or Dislike. Most people can generally convey their feelings about something in 5 levels: 1 - Hated it. 2 - Didn't like it 3 - Was OK 4 - Was good 5 - Was great As an example. With KZfaq's rating system, if one person Liked this video and one person Disliked it (and only two voted), then the average rating would be 50%. But if those same people could select a star rating and one person gave it 1 star and another 3 stars, the average would be 2, making the overall rating less than 50% and thus more accurately reflecting how well this video was liked.

"Fuzzify" should be word of the year.

I'm about 0.3 watching this video, doing work at the same time

Fuzzy Logic: robotics and A.I. will be impossible without it. (eg. even when I park my car, I don't know the exact distance between my car and the wall; I just know "the distance is good enough")

Good to hear you mention uncertainties there at the end -- such an important consideration. On a different point, I've always believed it somewhat insightful to think about its (fuzzy logic's) semantic contrast (and even its relation) to a probability concept, such as Bayesian inference (essentially, degrees of truth on the one hand, and prediction on the other).

Always a pleasure to have an explanation from Joe, and an interesting topic to boot.

Thanks for a new video that leaves me more confused on the subject than I was before!

I love all the different paradigms and sub-paradigms in software design!

is Zadeh the same guy who also came up with Z-transform and Z numbers?

Great vid. Thanks again Brady.

Thanks for explaining! I always wondered what this fuzzy logic, that my high-end Japanese rice cooker has, was exactly.

So how is the inference engine and the "fuzzification" any different from the IF functions. The system still has to interpret the inputs and define what they "are" based on certain parameters, correct?

These 3d animations are really good!

It sounds like the fizzy set is a percentage of the input in a given range of values. This would allow the rules to be relative and changing the range of the set fundamentally changes the operation of the entire program and its outputs. Genious! Bravo.

I don't quite understand. Is it mapping the values to something different [to express it in Java (or atleast Processing, which is the only language I know but apparently is almost the same as Java) newTemperature=map(dirtiness, 0, 1, 20, 60)], or is it assigning certain statuses ( if(dirtiness > 0.8){veryDirty = true})?

Interesting stuff. I happen to be taking a philosophical logic class at the moment, and it seems somewhat related.

So it's basically a work on ratios of data. It's like driving PWM to LED, you can light the LED at different brightness level, then you can measure an input signal as ADC voltage which is also a matter of ratio. Could this also be an example of fuzzy logic?

I didnt get it quite: I shouldnt use if statements but switch case? I mean you still have to do something when something happens?

The explanation is very clear. No trifling things!

I would like to see 'Dizzy Logic' where computers support repeat processes based on true events. Eg. If you are changing multiple file names the os would anticpate the process based on the processes that have previously taken place. Or if you copied files into a folder it would rename and sort files into subfolders based on file formats and gives all files and folders a relationship - certainly help keep file structures organised.

Really helpful! Great job explaining it!

Isn't the washing mashine example also just an awful lot of IF's, just running in the background? For example, the "dirty" state of the water is also a boolean and so is the "hot" state. And both of these states are eventually dependent on a set of IF's aren't they? For example someone would have determined that "hot" for the water means that the water's temperature is above 70°C and "dirty" means that the amount of dirt particles in the solution is above a certain level...

I've recently taken my first foray into this (using LabVIEW, though guess the platform isn't important), and took ages to understand the point of it - why not use something like a PID controller? Then suddenly I twigged, and feel like I've seen the light - and the light is fuzzy! Looking to build an ignition advance controller for my Mini now :)

"Fuzzy Expert Systems" is the name of my new line of sweaters.

So you're saying they go from an analog value to a digital value through a function to deal with them? It's almost like modulation and demodulation.

If you were coding this, wouldn't you have to explicitly define every member of a set? For instance if you had a set of pets, but you forgot a parakeet. Your member function would then return that a parakeet is not a pet (or 0.0 petness). How do you get around this? Do you have to use some form of machine learning like he said at 3:30?

Hmmm... I would have explained fuzzy logic exactly the other way round. You have a continuous rang of values, but modelling your systems with these values is too complicated. So, you limit your values to a discrete set, such as very hot, hot, warm, medium, cold, and very cold, instead of a centigrade value. Then your washing machine can easily use them for its calculations!?

How about some references to suggested reading etc (on all videos) if possible?

Could you please answer this question-why fuzzy concept is considered an extension of classical logic

As one of the mathy sorts of people, I found this very stimulating - the speaker in this video did a very good job. Cheers!

hello everyone can i get some paper or some books about Fuzzy logic & thier application on image processing PLZ??

And because of that graphic, now we need a computerphile tshirt!

9 minuets + a coherent example... it took my Tel-Aviv University Professor 3 hours to say the same thing in a confusing and frustrating way thanks for this vid :)

This guy is a lot better than the text by SMS guy.. A lot more natural

I would have liked to see what that actually looks like as code.

I love your interpretation of fuzzy logic. Its very clear. Please can you do a video showing how this would work if we were to use fuzzy logic to determine peoples risk bearing level

What's more interesting, in Fuzzy Logic the calculation rules for logical connectives are consistent with Boolean algebra (you get the same results if you restrict yourself to 0 and 1 and nothing in between), but they are different from probability theory, where they are also consistent with Boolean algebra.

It seems that fuzzy control and feedback control are same things; are the? Like example in the video- detergent added in washing machine is determined by "how dirty" cloths are and the same logic is used in feedback control.

What about using a PID to control water temp. If we have some set point that the user thinks is warm, the PID should be able to handle disturbances.

I always see fuzzy logic contrasted to binary logic. As if using more than one bit to make decisions in a computer was a complete revelation at the time. To me, without being an expert in fuzzy logic, the main feature of fuzzy logic is that it uses probabilities while the systems are still quite comprehensible _for humans_, and if it's only the developer of the expert system. So it's not that the computer is restricted in this case, it's us. _We_ can't handle neuronal weights or high-dimensional support vectors and still see what's happening in that washing machine.

Great video. Great explanation.

Brilliant video!!!

So we need to do EXPERIMENTAL DESIGN to get the FUZZY SETS, then defuzzy it to get OPERATIONAL SETTINGS. Is that correct? 😢

his washing machine is so much more advanced than mine!...

What is the difference between a pid system and a fuzzy logic system?

I've learned that the world can be black or white, just so long as you ask the right questions. Unfortunately it means you have to break EVERYTHING down to binary terms, which can take a single question and turn it into dozens, or even hundreds.

So basically, analog values?

could someone please tell me what laptop is that ?

Code using standard logic is easily maintainable and kept neat with the use of constant variables.

I don't get it... Isn't this just the same as dirty being a function? So instead of using certain variables in an if-statement you call a function, say isDirty() that will return true or false? And isDirty contains something like "if(temp < 30 && lumen < 1){ return true;}"

They neglected to mention that fuzzy logic is far more efficient, robust and reliable than non-fuzzy logic control systems.

so is fuzzy logic basically how one would make a controller with say, an arduino, without using some sort of mathematical model, but instead using boolean logic?

Thanks for the explanation!

What a nerdy T-shirt... and true also...

Wow, fascinating! I like this much better than a block of if's. It's much easier too!

Hey! How did you do in SpaceApps? I entered too :)

You should do something on LaTeX and Donald Knuth!

any idea how should begin with it in air pollution monitoring?

I an not a big computer science expert but isnt any complicated piece of code if fuzzy? I mean, the more conditions you have and the more cases you cover the fuzzier it becomes? so any code that have more than a simple if statement is fuzzy?

Excuse me for the ignorance, but how does this differ from control theory? I mean, the washing machine, train and shower temperature could all be solved within control theory, without resorting to yet another rather -for me - confusing concept

The founder of this logic is from my country Azerbaijan. We are so proud of him

Species are a great example of fuzzy logic.

It sounds to me like the coding used in fuzzy logic bears a strong similarity / compatibility with OOP. Where 'Fuzzy Set' ≈ 'Object', and 'Membership Function/Rule Base' ≈ 'Methods'?

where can I get the t-shirt?

You were correct. I am in England and it's chucking it down!

Great explanation thank you

2:55 Slayer - Raining Blood

Fuzzy Face Logic. Well done, sir! Great video!

But if 'nice weather' is defined the Law of excluded middle is applied and makes the statement "It's nice weather" either true or false. So in the end, you have only these two options. It's only a question of how you define things in the statement.

GREAT VIDEO

The weather in England is actually beautiful today for once!

from what I gathered from this video, "fuzzy logic" is simply a name for measuring something, and outputting a 1 or a zero depending on if the measured value cross some set threshold. Am I missing something here?

I see Joe is going for a 'fuzzy' look himself. Nice beard mate!

Oh wow I am in my last year of university and I have a subject called "softcomputing's application" and it is about ANN, fuzzy logic and genetic evolution. (They use something called xfuzzy)

Is Friday a weekend? The closer to morning it is, the closer the truth value is to 0. At 5pm, the truth value is around 0.5. After 8pm, the truth value gets much closer to 1.

This seems like pointless semantic sleight of hand. For example, if you want to adjust the spin speed of a washing machine based on the clarity of the water, just write a linear equation relating those two real-number variables. Why build this clunky, unintuitive thing on top of boolean logic when we've already got algebra?

So fuzzy logic is just assigning rules to ranges of values instead of specific values? That's it?

Schmit trigger is the perfect representation of fuzzy logic stands!

Very good explained. Yesterday we wrote an exam which had a Fuzzy-Logic question that was worth 15% of the points. I think i got all right.

Isn't this basically object oriented programming? Instead of writing a bunch of long if statements all over the place, having "fuzzy sets" that have pre packaged rules? Objects right?

thank you for very useful explanation :)

Great video!

i want to watch the kernel panic video so bad!!! just edit it already!!!!!!!!!!!!!!!

Watching Computerphile with only one eye opened; where's your logic now?

then Fuzzy logic is just a map from real value to (0,1)? why not work on the continuous variable directly？

Fuzzy logic is like a peach. Fuzzy.

I'm not sure how these fuzzy if's work at a fundamental level. What is the computer searching for?

Can we have a video on big data ?

2:55 ITS BLOOD!

You don't identify who is speaking in this video or in the comments.

I didn't really understand. Say you have that the water is half dirt half clean, then your "if" statement would require the washing machine stop cleaning and at the same time clean more. How does it decide what to do?

His macbook air looks just like mine! Lots of nerdy stickers!

I could break every thing you said down to two decisions. Ultimately the world is not 'gray' but is discrete. An electron can exist at one energy and move to another with no gray area. I think giving the users the best visualization w the collection of true/false decisions is what you are trying to get at

But "nice" is always subjective, meaning that it is defined by prior experience. What you find nice is determined by how it compares to the prior experienced states of things. But by finding something "nice", you still ask the same question, even though it is answered through different logic reasoning. Because by asking if someone finds a thing or state "nice", you merely ask him to compare it, but not for the base on which he grounds his answer.

How does it feel to feel ?