All Questions
682 questions
8
votes
2
answers
2k
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 ...
- 31.8k
20
votes
1
answer
1k
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 ...
- 543
3
votes
2
answers
161
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 ...
- 383
3
votes
1
answer
460
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 ...
- 2,361
5
votes
1
answer
670
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 ...
- 31.8k
1
vote
0
answers
333
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 <...
- 31.8k
25
votes
1
answer
6k
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
...
- 31.8k
13
votes
2
answers
3k
views
How to train a convolutional neural net on images?
The functions Predict[] and Classify[] both have the option Method -> "NeuralNetwork", ...
- 31.8k
15
votes
1
answer
474
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 ...
- 42.3k
21
votes
2
answers
2k
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 ...
- 1,582
11
votes
1
answer
406
views
How to view ClassifierFunction's preprocessed data?
Classify apparently preprocesses your input data, for example (same example from Classify reference page, but using ...
- 360
44
votes
1
answer
3k
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 ...
- 3,820
10
votes
1
answer
735
views
Mathematica learning resource dealing with bayesian inference
Is there any good resource dealing with both Mathematica and bayesian inference?
- 1,582
9
votes
2
answers
677
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 ...
- 205
6
votes
1
answer
387
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:
...
- 3,820
4
votes
0
answers
439
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 ...
- 2,046
13
votes
2
answers
2k
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 ...
- 968
2
votes
0
answers
958
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 ?
- 2,046
6
votes
1
answer
792
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:
...
- 319
15
votes
3
answers
2k
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:
...
- 1,393
8
votes
1
answer
743
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 ...
- 2,740
6
votes
1
answer
780
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:
...
- 2,855
7
votes
2
answers
1k
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 ...
- 173
18
votes
2
answers
3k
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.
- 598
7
votes
2
answers
142
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 ...
- 42.8k
40
votes
2
answers
2k
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 ...
- 3,820
2
votes
0
answers
1k
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 ...
- 111
16
votes
1
answer
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
votes
3
answers
1k
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 ...
- 1,867
7
votes
1
answer
901
views
Classify the classic tennis example
When using the classic tennis data (reference here) with Classify
...
20
votes
2
answers
5k
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 ...
- 978
6
votes
1
answer
723
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 ...
- 61