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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.

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3
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0answers
485 views

Pattern recognition

I am trying to have Mathematica come up with a simplified version of a real pattern. For the moment I'm trying with handwritten digits, but eventually I want to apply it to more complex photographs. ...
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3answers
525 views

Identify a scalar, a list

I have a symbolic scalar m2 and a symbolic list (representing a 3x3 matrix) A. I want a function which does something like: <...
2
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1answer
107 views

How to do multilabel multioutput classification?

Classify doesn't work when the targets are lists, so you need to encode the labels. However, there must be a nicer built-in way to do label encoding than this, but ...
15
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1answer
4k views

How to visualize a random forest classifier?

I'd like to recreate this visualization (from python) in Mathematica: I'm not sure how to extract the decision boundaries from a classifier with "Method" set to "RandomForest". Here's the code: <...
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0answers
334 views

What's the algorithm behind markov classifier in Classify function for text classification?

https://www.wolfram.com/mathematica/new-in-10/highly-automated-machine-learning/find-which-author-wrote-a-text.html The above url show the use of Classify ...
38
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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 ...
1
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0answers
53 views

How effect is the mathematica automatic machine learning function like `Classify`? [duplicate]

The documentation said use Classify, you will get state of the art machine learning result. But since the Classify function of ...
2
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1answer
429 views

Turning table into association for Classify

I have the following sample data for 20 users. I know their sex, and the response for three yes/no questions. I am trying to building a classifier to guess their response to the third question, based ...
1
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0answers
371 views

Uncorrected Versus Corrected Measures of StandardDeviation in PredictorMeasurements' “StandardDeviation”

When using Predict have noticed that the standard deviation of the residuals computed manually is not equal to the output from ...
7
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0answers
461 views

FindFormula Control [closed]

FindFormula is great start on the path to full symbolic regression and I realize it's level of development is only experimental at this stage. But if I happen to ...
7
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1answer
321 views

How to ImageIdentify multiple objects in a single image?

Suppose an image has multiple objects: ImageIdentify only finds the banana: ...
3
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0answers
78 views

What ratio of example per class gives best results and least overfitting?

For an n-class classifier or predictor, how many positive (or negative?) examples of each of the n classes should I put into my training and testing sets for the best results? I anticipate that ...
14
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2answers
1k views

How to detect loops in a vector field?

Given a vector field and I'd like to detect if there are streamlines in closed patterns. For example, if the input is a vector field like this: ...
4
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0answers
336 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 ...
12
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1answer
424 views

How to monitor the progress of training a classifier?

I've had p = Predict[x -> y] running for hours and I have now idea if I should kill it or not. I'm looking for some rough bounds for an estimate of how long <...
14
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2answers
2k views

Trainable WEKA segmentation of images

Is there a Mathematica equivalent of Trainable WEKA Segmentation as implemented in Fiji, the image processing software? A Google search did not return any relevant links. I attach the original image ...
6
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0answers
227 views

How to perform Bayesian optimization with Mathematica? [duplicate]

Does Mathematica have any Bayesian optimization methods for learning hyper-parameters? Practical Bayesian Optimization of Machine Learning Algorithms Jasper Snoek, Hugo Larochelle and Ryan P. ...
7
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1answer
540 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
134 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
160 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, ...
15
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1answer
408 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 ...
0
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0answers
98 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 ...
5
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0answers
252 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: ...
20
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1answer
937 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
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2answers
120 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 ...
5
votes
1answer
611 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
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0answers
308 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 <...
9
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1answer
516 views

Mathematica learning resource dealing with bayesian inference

Is there any good resource dealing with both Mathematica and bayesian inference?
8
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1answer
539 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 ...
7
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1answer
774 views

Classify the classic tennis example

When using the classic tennis data (reference here) with Classify ...
2
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0answers
813 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 ?
8
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1answer
587 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
629 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: ...
7
votes
2answers
912 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 ...
18
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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
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2answers
131 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 ...
16
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1answer
2k 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
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3answers
995 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 ...