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Questions tagged [classification]

The tag has no usage guidance.

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Cat Dog classifier in tensorflow, fundamental problem! [closed]

I am trying to build an image classifier for a set of images containing cats and dogs. I am very new to the dark art of creating Neural Network models. I have had success building models with Keras in ...
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1answer
24 views

SVM with a priori information about class probabilities

Given are two 2-d sets, each with its own bivariate normal distribution. I need to build an SVM classifier. The a priori probabilities of each class corresponds to the size of its set (20/50 for the ...
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46 views

Random Forest - Conditional Permutation Importance

I've been looking for the most unbiased algorithm to find out the feature importances in random forests if there are correlations among the input features. Besides the most commonly preferred ...
2
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1answer
32 views

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 ...
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44 views

Resource allocation / optimization

At work I stumbled across this problem of allocating resources: We are given a set of objects belonging to one of seven possible classes (multiple objects per class are allowed). We distinguish ...
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8 views

About cross-entropy loss

Is there a classification scenario with cross-entropy loss such that the loss as a function of the predictor/neural net's parameters is a function s.t it satisfies the properties of (a) having a ...
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0answers
25 views

Classify/Distinguish between 8008 binary grids, with 13 queries

I have $8008$ binary grids of size $6 \times 10$ (they are all grids with the property described below), which I want to distinguish between with at most $13$ queries. A query will determine if the ...
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1answer
22 views

Choose the best classifier to predict the label of strings of a regular language

I have to tackle this problem: I have some strings that are my training set. These strings belong to a regular language corresponding to a deterministic finite automata (hidden namely I don't now it, ...
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0answers
20 views

Classifying a problem involving matching bit arrays

First explaining the "reverse" use as a background: There is an array A which contains N boolean values There is an array B which contains N boolean values I start iterating over array A and for ...
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39 views

Why do reviewers always want to compare the method with deep learning baselines and Big data?

I work on the topics of sparse coding (SC) and dictionary learning (DL), in which classification is not the main goal, but the discriminative power of the representation is one of the concerns. ...
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2answers
58 views

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 ...
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1answer
28 views

How to show that i have significant improvements over the baselines?

I had review feedbacks regarding my recent publications and reviewers argued that the improvements are not significant over the baselines. I tried my classification algorithm on some image datasets ...
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57 views

Why don't Artificial Neural Networks Commonly Diverge?

Introduction: I'm using divergence here as to mean that the gradient is getting further and further from zero in stochastic gradient descent. I've written my own feed-forward neural network and tried ...
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2answers
77 views

The well-known classifiers that can be trained/tested in linear time [closed]

I am interested in collecting the list of the classifiers that (depending on their setting) can have linear time complexity (both in training and testing step) with respect to the number of samples $n$...
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1answer
25 views

How to find a possibility of match in Naive Bayes Classifier?

My math level is very very poor so I can't get the statistics. Can anyone explain in simple words? I.e. if I have frequency data: ...
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0answers
22 views

Attribute Selection for minimum number of clusters

I have a table consisting of some headers $P, Q, R, S$ (shown in blue in Table 1). According to the headers, the column $T$ is populated using some predefined logic. Now, any of the headers $P,Q,R,S$ ...
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2answers
371 views

What is a monotone dataset and monotone classification?

Classification algorithms, such as k-Nearest Neighbors, are well known in machine learning area, but I faced this new expression Monotone classification and I wonder what does it stand for. I guess ...
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0answers
70 views

Understanding Time Series Data for Classification

I have collected data from numerous volunteers driving a simulator in 8 different scenarios (classes). A volunteer drives in a map for 4 minutes in one scenario (one experiment), then he drives in the ...
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1answer
33 views

Feature selections : Still a high dimentionality

One of the advantage of using a features reduction/sub feature selection is to avoid a high dimentionality. The most known method is the Forward selection, where it finds the best combinations of ...
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0answers
128 views

(Percision & recall) Vs (Accuracy)? which one do I have to consider?

I am running several machine learning classifiers to predict something from my data. If I visualized the precision and recall tables as a result, is it enough to get clear idea about the proposed mdel?...
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2answers
1k views

What kind of pattern recognition algorithm would Facebook use to detect suicidal users?

Facebook announced that it would employ a machine learning "reporting process using pattern recognition in posts previously reported for suicide" (https://newsroom.fb.com/news/2017/03/building-a-safer-...
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0answers
26 views

Should I normalize values not bigger than 1

I have a question regarding a normalization of values especially in the case of image processing features classification. What if have a series of values that will never be bigger than 1. A = 0.004 0....
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1answer
422 views

Can a KD tree be used as a decision tree through nearest neighbor queries?

If I were to construct a KD tree representing a sufficiently dense space, could it be used as a decision tree by querying it for the nearest neighbor to the point to classify?
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44 views

Question about (in)dependent Haar-features and (Ada)boosting

I have an old exam question for my pattern recognition course which is stated as follows: Consider a pool of Haar features, determine if these Haar features are independent or not. Is it a problem ...
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1answer
233 views

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 ...
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0answers
74 views

Which Machine Learning algorithm should I use for gender tagging of words in NLP? [closed]

I have a dataset of about 26,000 words along with their gender tags [m, f or any]. Which ML algorithm should I use for Gender Tagging/Classification purpose. How should I go about it? What should be ...
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2answers
652 views

Scoring metric for machine learning method

For a machine learning method X (Deep Neural Nets variant), which performs classification tasks. In the output layer, for every label method, ...
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1answer
373 views

how to interpret the coefficients of binary logistic regression?

I'm working on a kNN classifier to classify whether a text is written by a man or a woman on the basis of the most frequent words. However, a kNN doesn't show which features were the most important in ...
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2answers
183 views

How to use Neural Network classification if data not same size?

I have data like this. [0 1 0 1 0] [0 1 0 1 0 1 1] [0 1 0 1 ] [0 1 0 1 0 1 1 1 1 0] ... I want to classify with Neural Network but my data different size . I can ...
2
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1answer
295 views

How to tackle different sample size in the training set in SVM

I have to train a SVM for a classification problem. I have some strings that are the paths in a deterministic finite automata (DFA). If the alphabet is -01- then possible strings are 011101110 or ...
3
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1answer
2k views

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)= \...
2
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1answer
64 views

Classifying objects by set proximity

The project I'm working on has a number of objects arranged in overlapping sets. I need to classify them by whether they have a trait or not, using pre-classified objects that they are connected to (...
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0answers
48 views

Machine Learning Algorithm Recommendation For Sensor Data [closed]

I would like to classify data coming from a sensor. In the literature Hidden Markov Model and SVM are used, but I would like to improve results with another methods.The picture how data and classes ...
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1answer
1k views

What is the different between Dijsktra's algorithm and KNN?

I am implementing machine learning software and in my case, I am using K-nearest neighbour classifier to get the task done. So far, I am trying to understand how Dijkstra's algorithm that has been ...
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2answers
318 views

Keywords for classification of 2D time series data?

Trying to find the right search terms for literature on classifying 2D time series data. I am looking at data from positional tracking of a swarm of insects over time. I have example datasets for ...
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1answer
59 views

Question about handwritten numbers recognition with limited data set

I have a an assignment to make a classifier for hand-written numbers with a limited data set of 500 samples. I am currently using python, I tried sklearn SVC with linear classifier and I got an ...
1
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1answer
214 views

How does an image classifier select relevant features?

I am trying to understand cascade classifiers for computer vision. I use OpenCV Traincascade for now and successfully trained some cascades. However I am trying to grasp the whole process. One thing ...
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0answers
49 views

Genetic algorithms, Pittsburg - Reach a decision from a set of rules

Consider a binary classification problem. In the Pittsburg approach each member of the population represents a set of rules. Each rule encodes information regarding the data features (that is, the ...
3
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2answers
242 views

Language Classification + AWS ML: what am I doing wrong?

I'm evaluating Amazon's machine learning platform, and thought that I would give it a "simple" classification problem first. As a disclaimer, I am quite new to machine learning (hence my interest in ...
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0answers
137 views

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 ...
0
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1answer
33 views

What is it called when you classify words into categories, but not by part of speech?

I'm looking to classify words into type categories like sushi to food, baseball to ...
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0answers
64 views

Problem with the motivation of penalized logistic regression

The following is a motivation for penalized logistic regression in some lecture notes I'm following: Although the cost-function for logistic regression is lower bounded by 0 we get issues if ...
3
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1answer
283 views

machine learning classification with financial instrument/time series data

I am new to machine learning and have started brainstorming some model ideas that involve financial instrument/time series data. I was thinking it might be useful to use a classification algorithm to ...
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0answers
135 views

Support Vector Machines vs K-Nearest Neighbors

Let's say we have trained a Support Vector Machine with a Gaussian Kernel. When we feed our model an example, it classifies it based on its similarity to landmarks (distance to examples in our ...
3
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1answer
206 views

What method of collective recogintion to use for digits recognition?

The structure of the question is as follows: at first, I provide the concept of collective recognition, further I provide explanation of the various methods of group classification that I found, in ...
3
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2answers
817 views

What is a sparse classifier?

Given a two-dimensional data set where each point is labeled $ \{0,1\}$, I want to implement a sparse classifier with $L_p \ \text({ 0<p \leq 1) }$. I have been reading on logistic regression and ...
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1answer
60 views

Find string patterns preferably in regex for string streams

I am trying to classify the data in a database columns. DB has about 90 million entries.The main goal is to find different patterns in columns to leverage it for create look alike data. The data ...
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2answers
2k views

Simple majority classifier question

one of my training questions for my exam is the following one: Suppose you are testing a new algorithm on a data set consisting of 100 positive and 100 negative examples. You plan to use leave-...
2
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1answer
623 views

Dynamically Learning Haar Cascade (in OpenCV)

I am new to computer vision so please excuse me if this question is very simple. I am trying to learn how to use the Haar Cascade creation tool provided with OpenCV to train a cascade classifier. It ...
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1answer
52 views

classifier accuracy

I’m developing a mutual information based classifier, the output of the classifier is {{0,4,5,6},{1,2,3},{7},{8},{9}} and the correct decision output is {{0,1,2,4,5,6,9},{3},{7,8}}. How to compute the ...