Questions tagged [classification]
148 questions
11
votes
2 answers
A text-classifier that explains its decisions
I am building a text categorizer for short sentences. In addition to telling the user "the category of the text you entered is C", I want to be able to explain why I made this decision, in a short and understandable way. For example, I don't want…
Erel Segal-Halevi
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9
votes
3 answers
When should I move beyond k nearest neighbour
For many machine learning projects that we do, we start with the k Nearest Neighbour classifier. This is an ideal starting classifier as we usually have sufficient time to calculate all distances and the number of parameters is limited (k, distance…
Rhand
8
votes
1 answer
Size of decision tree and depth of decision tree
I'm doing some classification experiments with decision trees ( specifically rpart package in R). By setting the depth of a decision tree to 10 I expect to get a small tree but it is in fact quite large and its size is 7650. So what is exactly the…
user
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8
votes
2 answers
VC dimension of linear separator in 3D
I am confused about the Vapnik-Chervonenkis dimension of a linear separator in 3 dimensions.
In three dimensions, a linear separator would be a plane, and the classification model would be "everything on one side of a plane."
It's apparently…
Jason Smith
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7
votes
0 answers
What machine learning method for diabetes prediction SW?
I'm thinking of an application for diabetics, that, given previous values of blood glucose and insulin dosage, predicts the glucose level for the next few hours.
I know a few things about neural networks and perceptrons, but not much. And there are…
Martin Janiczek
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7
votes
1 answer
Algorithm to find a line that divides the number of points equally
I have recently been asked in an interview to devise an algorithm that divides a set of points in a coordinate system so that half of the points lie on one side of the line, and the rest on the other side.
The points are unevenly placed and the line…
Ravi Teja
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6
votes
1 answer
Showing that Bayes classifier is optimal
Consider domain $X$, label set $ Y=\{0,1\}$ and the zero-one loss.
Given any probability distribution D over $ X\times \{0,1\} $, we've defined the Bayes classifier $ f_D $ to be-
$$ f_{D}(x)=
\begin{cases}
1 & \text{if…
Alex Goft
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6
votes
1 answer
Theory of multi-label classification
Multi-label classification is a machine-learning problem where each sample can have zero or more labels from a closed set of possible labels. This task has applications in several fields. For example, in dialog systems, each sentence that the human…
Erel Segal-Halevi
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5
votes
2 answers
Given $k$ points in $n$-dimensions, such that $n\geq3$, is there a polytime algorithm for finding a curve that splits them into 2 sets of points?
So in this math exchange question I asked, it was proven that for $n>2$ dimensions, you can always find a curve that separates $k$ points in $n$-dimensional space into $2$ arbitrary sets that you pre-defined. What I wanted to know is if there is a…
wjmccann
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5
votes
1 answer
What is a good approach to symbol identification/recognition given a path, instead of raster data
Excuse any mistakes in my description as I'm new to ML. But I have an application that takes user input to generate paths/curves (All symbols are single paths) and I would then like to attempt identification. This seems, generally, to be a pretty…
Arelius
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5
votes
1 answer
Advantages of adaboost over gentleboost in applications, or vice versa?
I've been researching on AdaBoost and GentleBoost classifiers, but can't seem to find a clear answer to the question:
What is Adaboost better at classifying in computer vision?
What is GentleBoost better at classifying?
I've been told that…
user961627
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5
votes
3 answers
Word classification algorithms
I am looking for algorithms to classify words in a paragraph of text. I am particularly interested in a classification to determine if a certain word is noun, verb, etc., but also looking for any kind of word-classification algorithms. I am given a…
gen
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5
votes
1 answer
k-means clustered data: how to label newly incoming data
I have a data set with labels that were produced by a $k$-means clustering
algorithm. Now there is some data (with the same data structure) from another
source and I wonder what is the most sensible way to label this new, yet unseen
data? I was…
Uli Niklas
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4
votes
0 answers
What are the best features to identify heads from any angle?
I want to automatically track heads in CCTV records.
Sometimes I need to re-identify heads because of multiple heads crossing each other. So I continually need to extract features from tracked heads so that I will be able to re-identify them when…
Dubrzr
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