What's the main difference of PAC learning and agnostic PAC learning? - machine-learning

I'm studing machine learning and I occurred in the PAC lerning, I don't understand the differenes between PAC learning and Agnostic PAC learning.
I tried to search it on internet but I did not found anything very clear and I ask it tu ChatGPT and it answer me that the Agnosic one does not consider the distribution D, that I don't think is true beacuese in the Agnostic definition the distribution D appears.

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Is there a native library written in Julia for Machine Learning?

I have started using Julia.I read that it is faster than C.
So far I have seen some libraries like KNET and Flux, but both are for Deep Learning.
also there is a command "Pycall" tu use Python inside Julia.
But I am interested in Machine Learning too. So I would like to use SVM, Random Forest, KNN, XGBoost, etc but in Julia.
Is there a native library written in Julia for Machine Learning?
Thank you
A lot of algorithms are just plain available using dedicated packages. Like BayesNets.jl
For "classical machine learning" MLJ.jl which is a pure Julia Machine Learning framework, it's written by the Alan Turing Institute with very active development.
For Neural Networks Flux.jl is the way to go in Julia. Also very active, GPU-ready and allow all the exotics combinations that exist in the Julia ecosystem like DiffEqFlux.jl a package that combines Flux.jl and DifferentialEquations.jl.
Just wait for Zygote.jl a source-to-source automatic differentiation package that will be some sort of backend for Flux.jl
Of course, if you're more confident with Python ML tools you still have TensorFlow.jl and ScikitLearn.jl, but OP asked for pure Julia packages and those are just Julia wrappers of Python packages.
Have a look at this kNN implementation and this for XGboost.
There are SVM implementations, but outdated an unmaintained (search for SVM .jl). But, really, think about other algorithms for much better prediction qualities and model construction performance. Have a look at the OLS (orthogonal least squares) and OFR (orthogonal forward regression) algorithm family. You will easily find detailed algorithm descriptions, easy to code in any suitable language. However, there is currently no Julia implementation I am aware of. I found only Matlab implementations and made my own java implementation, some years ago. I have plans to port it to julia, but that has currently no priority and may last some years. Meanwhile - why not coding by yourself? You won't find any other language making it easier to code a prototype and turn it into a highly efficient production algorithm running heavy load on a CUDA enabled GPGPU.
I recommend this quite new publication, to start with: Nonlinear identification using orthogonal forward regression with nested optimal regularization

Need answer about some Machine Learning related questions?

Recently, we planned to build a system for image processing to extract info from images. At present we are using AWS Rekognition to do that. But, in some cases, we are not getting accurate information from AWS. So, we've planned to build our own custom one.
We've 4/5 months to do that. At least a POC version. Also, we've planned to use Tensorflow for that. We all have no prior experience about Machine Learning & Deep Learning but already have 5/6yrs of experience on Computer Programming by using different languages.
Currently, I'm studying ML from a course of Udemy & my approach to solve this problem is...
Learn Machine Learning(ML)
Learn Deep Learning(DL)
Above ML & DL maybe I'll be ready to understand the whole thing & can able to build a system for Image Processing.
In abstract what I've understood is, I've to write one Deep Learning program in Python by using Tensorflow. By using that Program I've to build a Model. Then I've to train that Model by using some training data. Then, when my Model achieves a certain level of accuracy I'll use some test data.
Now, there some places at where I've bit confused & here are my questions regarding that confusion...
I know tensorflow is a library but at some places, it's also mentioned as a system. So, is it really a library(piece of code) only & something more than that?
I got some Image Processing Python code in Tensorflow tutorial section (https://www.tensorflow.org/tutorials/image_recognition). We've tested that code & it's working exactly the way AWS Recognition service work. So, here my doubt is... can I use this Python code as it is in our production work?
After train a model with some training data does those training data get part of the whole system or Machine Learning Model extract some META info from those training data & keep with itself rather whole raw training data(in my case it'll be raw images).
Can I do all these ML+DL programmings over my Linux System? It has Pentium 4 with 8GB RAM.
Also, want to know... the approach which I've mentioned to build a solution for my problem is sufficient or I need to do something else also.
Need some guidance to clear out all these confusion.
Thanks
1 : tensor-flow is like anything else we have been worked with (like Numpy ) but only difference is we have to first defined what we want to use the use it , every thing in tensor-flow are running into a computational graph and evaluating every thing in that graph require a Session , we could call it library because it just piece of code and have interface in python , and system because of all those mechanism it uses
2 :
can I use this Python code as it is in our production work? Why not !
3:
yes you could do that with your system , but the main advantage of tensor-flow and theano , .. the tool like those is that you could run your code on GPU it a more faster way than on CPU because the GPU could handle a lot more matrix multiplication and stuff like that
4:
you know you don't have to learn all the machine learning stuff to built a image recognition system , it may be take years for you to understand whats going on there , Udemy course is very good source but you I highly recommend you to see the machine learning courses of coursera , there is to courses there about machine learning : the great Andrew NG course and Emily fox course , the first one is more theoretical than practical , but second on is more practical ,
and about the Deep learning , there is nothing fancy about Deep learning and it's just a method in machine learning , after you gain some experience in machine learning and understood some basic or you could do it right know , go to fast.ai , it has a really good course about deep learning for coder and it's also free
I hope this will help you

Suggestions for machine learning toolset without Matlab

I am new to the field of machine learning, I am planning to use python as the programing language for implementing algorithms and Java for system architecture.
As far as I understand, machine learning is more about modeling data specific to the domain, visualize the data, and choose appropriate models & parameters. Implementing the models/algorithms is the last and relatively easy step.
Matlab seems to have everything for machine learning but it is too expensive and requires to learn a new language.
What tools other than programming language do I need in general for machine learning for enterprise projects? things like data modeling, visualization,etc
After a couple of years of trial and error, I would suggest you to go directly with python, possibly with scikit-learn or tensorflow (if you want to go hardcore :).
I also tried R in the past, and while it is a very valid language it has some limitations: It is single threaded by default, and although there are solutions for that, they are non as clean as python.
Also, python seems to be THE language for machine learning, it is easy to learn, and fast (depending on the interpreter implementation of course), also there is huuuuuuge support for it, lots of tutorials, documentation and, more important, libraries are actively develop and supported.
Finally, i recommend you to consider spyder as a good IDE for data science, I also tried Rodeo, but it does not seem as mature and stable as spyder.
Hope this helps.

How are machine learning techniques used in automated theorem proving?

Logical proof can be viewed as searching for a path that leads from premises to conclusions, where each step is the application of an inference rule. I wonder how machine learning techniques can help find heuristics that limit the search for solutions into a smaller sample size.

What is machine learning? [closed]

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What is machine learning ?
What does machine learning code do ?
When we say that the machine learns, does it modify the code of itself or it modifies history (database) which will contain the experience of code for given set of inputs?
What is a machine learning ?
Essentially, it is a method of teaching computers to make and improve predictions or behaviors based on some data. What is this "data"? Well, that depends entirely on the problem. It could be readings from a robot's sensors as it learns to walk, or the correct output of a program for certain input.
Another way to think about machine learning is that it is "pattern recognition" - the act of teaching a program to react to or recognize patterns.
What does machine learning code do ?
Depends on the type of machine learning you're talking about. Machine learning is a huge field, with hundreds of different algorithms for solving myriad different problems - see Wikipedia for more information; specifically, look under Algorithm Types.
When we say machine learns, does it modify the code of itself or it modifies history (Data Base) which will contain the experience of code for given set of inputs ?
Once again, it depends.
One example of code actually being modified is Genetic Programming, where you essentially evolve a program to complete a task (of course, the program doesn't modify itself - but it does modify another computer program).
Neural networks, on the other hand, modify their parameters automatically in response to prepared stimuli and expected response. This allows them to produce many behaviors (theoretically, they can produce any behavior because they can approximate any function to an arbitrary precision, given enough time).
I should note that your use of the term "database" implies that machine learning algorithms work by "remembering" information, events, or experiences. This is not necessarily (or even often!) the case.
Neural networks, which I already mentioned, only keep the current "state" of the approximation, which is updated as learning occurs. Rather than remembering what happened and how to react to it, neural networks build a sort of "model" of their "world." The model tells them how to react to certain inputs, even if the inputs are something that it has never seen before.
This last ability - the ability to react to inputs that have never been seen before - is one of the core tenets of many machine learning algorithms. Imagine trying to teach a computer driver to navigate highways in traffic. Using your "database" metaphor, you would have to teach the computer exactly what to do in millions of possible situations. An effective machine learning algorithm would (hopefully!) be able to learn similarities between different states and react to them similarly.
The similarities between states can be anything - even things we might think of as "mundane" can really trip up a computer! For example, let's say that the computer driver learned that when a car in front of it slowed down, it had to slow down to. For a human, replacing the car with a motorcycle doesn't change anything - we recognize that the motorcycle is also a vehicle. For a machine learning algorithm, this can actually be surprisingly difficult! A database would have to store information separately about the case where a car is in front and where a motorcycle is in front. A machine learning algorithm, on the other hand, would "learn" from the car example and be able to generalize to the motorcycle example automatically.
Machine learning is a field of computer science, probability theory, and optimization theory which allows complex tasks to be solved for which a logical/procedural approach would not be possible or feasible.
There are several different categories of machine learning, including (but not limited to):
Supervised learning
Reinforcement learning
Supervised Learning
In supervised learning, you have some really complex function (mapping) from inputs to outputs, you have lots of examples of input/output pairs, but you don't know what that complicated function is. A supervised learning algorithm makes it possible, given a large data set of input/output pairs, to predict the output value for some new input value that you may not have seen before. The basic method is that you break the data set down into a training set and a test set. You have some model with an associated error function which you try to minimize over the training set, and then you make sure that your solution works on the test set. Once you have repeated this with different machine learning algorithms and/or parameters until the model performs reasonably well on the test set, then you can attempt to use the result on new inputs. Note that in this case, the program does not change, only the model (data) is changed. Although one could, theoretically, output a different program, but that is not done in practice, as far as I am aware. An example of supervised learning would be the digit recognition system used by the post office, where it maps the pixels to labels in the set 0...9, using a large set of pictures of digits that were labeled by hand as being in 0...9.
Reinforcement Learning
In reinforcement learning, the program is responsible for making decisions, and it periodically receives some sort of award/utility for its actions. However, unlike in the supervised learning case, the results are not immediate; the algorithm could prescribe a large sequence of actions and only receive feedback at the very end. In reinforcement learning, the goal is to build up a good model such that the algorithm will generate the sequence of decisions that lead to the highest long term utility/reward. A good example of reinforcement learning is teaching a robot how to navigate by giving a negative penalty whenever its bump sensor detects that it has bumped into an object. If coded correctly, it is possible for the robot to eventually correlate its range finder sensor data with its bumper sensor data and the directions that sends to the wheels, and ultimately choose a form of navigation that results in it not bumping into objects.
More Info
If you are interested in learning more, I strongly recommend that you read Pattern Recognition and Machine Learning by Christopher M. Bishop or take a machine learning course. You may also be interested in reading, for free, the lecture notes from CIS 520: Machine Learning at Penn.
Machine learning is a scientific discipline that is concerned with the design and development of algorithms that allow computers to evolve behaviors based on empirical data, such as from sensor data or databases. Read more on Wikipedia
Machine learning code records "facts" or approximations in some sort of storage, and with the algorithms calculates different probabilities.
The code itself will not be modified when a machine learns, only the database of what "it knows".
Machine learning is a methodology to create a model based on sample data and use the model to make a prediction or strategy. It belongs to artificial intelligence.
Machine learning is simply a generic term to define a variety of learning algorithms that produce a quasi learning from examples (unlabeled/labeled). The actual accuracy/error is entirely determined by the quality of training/test data you provide to your learning algorithm. This can be measured using a convergence rate. The reason you provide examples is because you want the learning algorithm of your choice to be able to informatively by guidance make generalization. The algorithms can be classed into two main areas supervised learning(classification) and unsupervised learning(clustering) techniques. It is extremely important that you make an informed decision on how you plan on separating your training and test data sets as well as the quality that you provide to your learning algorithm. When you providing data sets you want to also be aware of things like over fitting and maintaining a sense of healthy bias in your examples. The algorithm then basically learns wrote to wrote on the basis of generalization it achieves from the data you have provided to it both for training and then for testing in process you try to get your learning algorithm to produce new examples on basis of your targeted training. In clustering there is very little informative guidance the algorithm basically tries to produce through measures of patterns between data to build related sets of clusters e.g kmeans/knearest neighbor.
some good books:
Introduction to ML (Nilsson/Stanford),
Gaussian Process for ML,
Introduction to ML (Alpaydin),
Information Theory Inference and Learning Algorithms (very useful book),
Machine Learning (Mitchell),
Pattern Recognition and Machine Learning (standard ML course book at Edinburgh and various Unis but relatively a heavy reading with math),
Data Mining and Practical Machine Learning with Weka (work through the theory using weka and practice in Java)
Reinforcement Learning there is a free book online you can read:
http://www.cs.ualberta.ca/~sutton/book/ebook/the-book.html
IR, IE, Recommenders, and Text/Data/Web Mining in general use alot of Machine Learning principles. You can even apply Metaheuristic/Global Optimization Techniques here to further automate your learning processes. e.g apply an evolutionary technique like GA (genetic algorithm) to optimize your neural network based approach (which may use some learning algorithm). You can approach it purely in form of a probablistic machine learning approach for example bayesian learning. Most of these algorithms all have a very heavy use of statistics. Concepts of convergence and generalization are important to many of these learning algorithms.
Machine learning is the study in computing science of making algorithms that are able to classify information they haven't seen before, by learning patterns from training on similar information. There are all sorts of kinds of "learners" in this sense. Neural networks, Bayesian networks, decision trees, k-clustering algorithms, hidden markov models and support vector machines are examples.
Based on the learner, they each learn in different ways. Some learners produce human-understandable frameworks (e.g. decision trees), and some are generally inscrutable (e.g. neural networks).
Learners are all essentially data-driven, meaning they save their state as data to be reused later. They aren't self-modifying as such, at least in general.
I think one of the coolest definitions of machine learning that I've read is from this book by Tom Mitchell. Easy to remember and intuitive.
A computer program is said to learn from experience E with respect to some class of tasks T and performance measure P, if its performance at tasks in T, as measured by P, improves with experience E
Shamelessly ripped from Wikipedia: Machine learning is a scientific discipline that is concerned with the design and development of algorithms that allow computers to evolve behaviors based on empirical data, such as from sensor data or databases.
Quite simply, machine learning code accomplishes a machine learning task. That can be a number of things from interpreting sensor data to a genetic algorithm.
I would say it depends. No, modifying code is not normal, but is not outside the realm of possibility. I would also not say that machine learning always modifies a history. Sometimes we have no history to build off of. Sometime we simply want to react to the environment, but not actually learn from our past experiences.
Basically, machine learning is a very wide-open discipline that contains many methods and algorithms that make it impossible for there to be 1 answer to your 3rd question.
Machine learning is a term that is taken from the real world of a person, and applied on something that can't actually learn - a machine.
To add to the other answers - machine learning will not (usually) change the code, but it might change it's execution path and decision based on previous data or new gathered data and hence the "learning" effect.
there are many ways to "teach" a machine - you give weights to many parameter of an algorithm, and then have the machine solve it for many cases, each time you give her a feedback about the answer and the machine adjusts the weights according to how close the machine answer was to your answer or according to the score you gave it's answer, or according to some results test algorithm.
This is one way of learning and there are many more...

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