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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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6
votes
1answer
525 views

How to import/export to libsvm?

Under the hood Mathematica uses libsvm, so I don't think this question is beyond the pale. I need to export an svm I trained with Classify to the standard SVM Format (which is readable by libsvm). ...
4
votes
0answers
87 views

Create an adequate 'training set' to train a ClassifierFunction which performs the role of the built-in `SubsetQ`

I am trying to "grow" my own SubsetQ function using Machine Learning methods. My cSubsetQ when given two lists (listA and listB)...
4
votes
0answers
200 views

Classification problem using SVM methods

I am running SVM on mathematica and I a used this code with classes: ...
4
votes
0answers
288 views

How is the multi-class support vector machine classifier implemented? [closed]

I am using support vector machine (SVM) method with Classify to do multi-class. Can anyone tell me the reference (paper) used by Wolfram Mathematica to develop the ...
5
votes
0answers
111 views

How can I change the distance function in Classify when using NearestNeighbor?

Issue not present in version "10.4.1 for Linux x86 (64-bit) (April 11, 2016)" ...
1
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0answers
103 views

Using Classifier with NearestNeighbors methods

I am using a Machine learning toolbox on mathematica. I have 8 classes. Training data: for each class, there 100 samples with size 160. I used this code. ...
2
votes
1answer
203 views

Convert table data to Classifier data

I want to convert excel data into Classifier acceptable data. For Eg, the inbuilt Titanic data for Classifier is structured as below: {"1st", 29., "female"} -> "survived" I have 4 columns in Excel ...
9
votes
1answer
1k views

How can I determine the importance of variables from Classify?

I have used the "RandomForest" method in Classify to classify my response variable (nominal with 2 levels). Can Classify, like ...
5
votes
1answer
126 views

How to avoid crashing with ConformImages?

ConformImages[] is causing a kernel crash when applied to a list of 5k images. Is there any way to apply ConformImages on the list in batches or asynchronously to ...
3
votes
0answers
473 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. ...
2
votes
1answer
106 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
votes
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: <...
1
vote
0answers
330 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 ...
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 ...
7
votes
1answer
354 views

How to know the internal pre-processing of automatic machine learning function `Classify`?

In the Highly automatic machine learning page, it is said the function like Classify and Predict will do things like automatic ...
2
votes
1answer
414 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
vote
0answers
348 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 ...
13
votes
1answer
1k views

Is there any decent deep learning library in Mathematica?

Deep Learning is the currently trending method in machine learning community. Some languages like python and matlab have some very convenient toolbox for deep learning. So is there any decent deep ...
7
votes
0answers
442 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
votes
1answer
302 views

How to ImageIdentify multiple objects in a single image?

Suppose an image has multiple objects: ImageIdentify only finds the banana: ...
3
votes
0answers
75 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 ...
11
votes
1answer
275 views

Can Predict/Classify be parallelized?

Being able to parallelize Predict /Classify would be useful on multiple fronts: Performance/Scale Streaming Pedagogical ...
14
votes
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: ...
14
votes
3answers
767 views

Inverse of Interpreter[“Color”]: Convert a RGBColor to a natural language color name

What is the best way to create the inverse function of Interpreter["Color"]? That function takes a natural language color name like ...
12
votes
1answer
423 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 <...
1
vote
3answers
482 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: <...
36
votes
3answers
2k views

What is behind experimental function: FindFormula?

In version 10.2 there is a new experimental function: FindFormula[]. I suspect that a genetic programming algorithm (symbolic regression) is behind this new ...
14
votes
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 ...
65
votes
8answers
10k views

What are the Wolfram Language's relative strengths for machine learning?

I see a low use of Mathematica in Kaggle competitions. Why would one use the Wolfram Language versus R, Python, or Julia for machine learning? Besides prettier plots and the Manipulate function, ...
11
votes
1answer
928 views

Neural Networks in Predict function

I'm trying to reproduce the result giving by a Predict function with a Neural Network as the chosen method. So, I'm training from this set: ...
6
votes
0answers
219 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
votes
1answer
525 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
votes
0answers
133 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
votes
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, ...
3
votes
0answers
73 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
95 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 ...
4
votes
0answers
244 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
547 views

Softmax Regression implementation

...
7
votes
2answers
1k 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
920 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
119 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
393 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
605 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
304 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
3k 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
405 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
309 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 ...