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Questions tagged [machine-learning]

Questions about machine learning functionality of Mathematica, for instance involving, but not restricted to, Predict, Classify, FindClusters and the various regression functions.

7
votes
1answer
491 views

Using ImageIdentify

How long does it take ImageIdentify to give an answer for one image? Also, I suppose using it requires an Internet connection with Wolfram servers. Is that correct?
3
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0answers
129 views

How does Mathematica automatically choose which classifier method to use?

I'm interested in what heuristics are used in Classify's choice of method.
2
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4answers
156 views

Pairs of data to Classify[]

Suppose I had the following data a={1,2,3,4,5} How would I turn this into b={{1,2,3}->4,{2,3,4}->5} That is, ...
3
votes
0answers
71 views

Display of ConfusionMatrixPlot depends on Stylesheet [duplicate]

I´m using Classify and do the testing via ClassifierMeasurements. Now I observed that ConfusionMatrixPlot is not shown correctly when using StyleSheet Report(default). Maybe you can reproduce (example ...
0
votes
0answers
89 views

Classify: other output representation

I'm working on a classisfy problem. The code is like: CMDDrf = Classify[trainingdata, Method -> "RandomForest"] Then I want to make a prediction based on a ...
3
votes
0answers
223 views

Exporting Classify Models

Currently I have created a simple classifier to classify sentiment from a string of text (or a tweet). The code is very basic and looks something like this: ...
10
votes
1answer
533 views
6
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2answers
928 views

How to do $ n $-fold cross validation with Classify?

Other machine learning libraries have utilities to generate indices that can be used to generate dataset splits according to different cross-validation strategies. How do I tell ...
20
votes
1answer
859 views

Biased results when using Method -> “RandomForest” in Predict

I am interested in using random forests for some prediction, so I have been using Predict. I find that "RandomForest" method ...
3
votes
2answers
115 views

Slow application of `Outer` on a matrix

I have some performance issue with the calculation of a gaussian kernel applied to a not-that-large dataset. I'm not very good with performance tuning in Mma and I have the feeling this one could be ...
3
votes
1answer
352 views

Using a dataset of PredictorFunctions

I have been working with a dataset of predictor functions -- mainly so I can have more insight in to what the functions are doing and how they behave. Where I am struggling is using ...
5
votes
1answer
562 views

How can I train a binary classifier to find a logo?

So I'm trying to contruct a simple binary classifier. Problem: Classify an image as containing the apple logo, or not. I'd like it to be distortion, color, size and rotationally invariant. I'm sure ...
1
vote
0answers
288 views

When using Classify[] on images, is preprocessing necessary?

If the images in the training data set have different sizes and channels and color spaces, will this hinder the classifier? The examples in the documentation seem to suggest that normalization with <...
23
votes
1answer
2k views

How can I detect if an image is of poor quality?

I need to filter out blurry or otherwise bad quality images from a set. I would like an efficient method to detect images that have any of the following three attributes: Out of focus or motion blur ...
13
votes
2answers
2k views

How to train a convolutional neural net on images?

The functions Predict[] and Classify[] both have the option Method -> "NeuralNetwork", ...
15
votes
1answer
349 views

Rapid density estimation and rendering of decision regions

I would like to create an interactive demonstration using Manipulate[] that illustrates a fundamental concept in pattern classification and machine learning. This ...
20
votes
2answers
1k views

How to know the internal algorithms of functions like Predict or Classify?

The document centre seems only explain how to use these functions, but just in an very brief way. I know Mathmatica is not open source, so we can not expect to see the code of the function, but are ...
11
votes
1answer
274 views

How to view ClassifierFunction's preprocessed data?

Classify apparently preprocesses your input data, for example (same example from Classify reference page, but using ...
38
votes
1answer
2k views

How to perform document classification (i.e. extracting topics from text)?

I need to build a multi-label text classifier. There are a bunch of techniques for doing this, and it's called automatic document classification. I'm trying to use the EM technique (expectation ...
9
votes
1answer
462 views

Mathematica learning resource dealing with bayesian inference

Is there any good resource dealing with both Mathematica and bayesian inference?
8
votes
1answer
502 views

How do I access the parameters in Classify using Support Vector Machine as method?

I have a dataset that I want to classify and I do the following: clf = Classify[xtrain -> ytrain, Method -> "SupportVectorMachine"] How can I use my own ...
4
votes
1answer
281 views

What are the possible values of sub-options for Classify[]?

Specifically, how can I find the possible values of sub-option "KernelType" of option "Method" for Classify? Here's an example: ...
4
votes
0answers
299 views

How to make distance transform invariant to scale?

I am trying to use a distance transform as a descriptor to encode silhouettes in order to do a shape recognition task. It is clear that distance transform distribution is invariant under rotation and ...
13
votes
2answers
1k views

How to change NeuralNetwork options?

How can I manipulate the architecture and problems of a NeuralNetwork in Predict or Classify? For example, running the following ...
2
votes
0answers
717 views

Max iterations in K-means clustering algorithm

I want to use k-means for clustering. I have used the ClusteringComponents function but I said how can I control the max-iteration for k-means ?
5
votes
1answer
639 views

Classify Function : Sentiment Polarity

I have been working on a project involving the new Classify[] function. More specifically, the sentiment analysis function. It works perfectly well, as in the documentation: ...
13
votes
3answers
1k views

Transform Dataset so it can be used as training set for Classify

Trying to learn the new Dataset features, I am playing with the iris dataset: ...
7
votes
1answer
507 views

Using Predict on images

I have a dataset of some (grayscale) images (stored as a list in inputImages) varying in size and content (this is example data from Wolfram, so you can run the ...
6
votes
1answer
583 views

Sentiment analysis of tweets

I want to use Mathematica for a sentiment analysis on tweet-messages. For that purpose i selected several tweets. Each tweet is interpreted by myself as positive (pos) of negative (neg). For example: ...
6
votes
2answers
791 views

Importing multiple images for machine learning classification

I want to create a ML classifier using images just like this example. I have two classes of images in two different folders. Is there an easier way to import all images from both folders rather than ...
16
votes
1answer
2k views

How to split a Dataset into training and testing for machine learning?

Suppose I have iris data In the Dataset Format. How to split the iris data Into training and testing for Machine learning? For example,Transform the data for Classify.
6
votes
2answers
127 views

ClassifierInformation's “ClassPriors” misreporting?

To the TLDR people It seems to me that when you explicitly set ClassPriors when running Classify, it creates a ...
31
votes
1answer
1k views

How can I export my learned ClassiferFunction[] and PredictorFunction[]s?

Mathematica 10 provides beautiful high-level machine learning functionality. Sadly, the learned functions once created are rather opaque objects. I need to use them in other projects, so here is my ...
2
votes
0answers
559 views

How do I obtain the Fisher Information Matrix from a data set?

My apologies in so much as this is probably in large part a problem of me not being aware of the necessary mathematics but since this should be a common issue in machine learning and Mathematica now ...
15
votes
1answer
1k views

Classify command in Mathematica 10

Where can I find documentation about the methods used in the Classify command in Mathematica 10? Specifically, how does the method ...
2
votes
3answers
841 views

Clustering data sets with multiple variables

I am learning how to cluster large datasets and this maybe a newbie question, but I haven’t found a suitable answer in the Documentation or on this board. My question is best illustrated by an ...
6
votes
1answer
715 views

Classify the classic tennis example

When using the classic tennis data (reference here) with Classify ...
16
votes
2answers
4k views

Machine learning. SVM algorithm

I want to work with machine learning in Mathematica. Are there any SVM algorithms implemented in Mathematica anywhere? Or any other algorithms for machine learning? With positive and negative database ...
6
votes
1answer
678 views

Unsupervised Machine Learning Algorithm for Autonomous Image Processing and Tracking

I am trying to prototype a Mathematica application that will enable Autonomous Intruder & Anomalous Event Detection, Tracking and Alarm to web users those who want to autonomously and ...