Questions tagged [classifier]

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Classification for different thresholds

Betting markets offer betting lines for football matches, where you can bet over or under x offside for a team. For example, for one match they can offer U4.5 offside with odds 2.0/2.0 (lets assume ...
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30 views

Credit scorecard model

Could anyone point me to a blog or content that talks about creating credit scorecards without logistic regression models? Instead, if we use an ensemble technique, such as random forest, how can we ...
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1answer
41 views

How is there an inverse relation between precision and recall?

What I know? Firstly, Precision= $\frac{TP}{TP+FP}$ Recall=$\frac{TP}{TP+FN}$ What book says? A model that declares every record has high recall but low precision. I understand that if predicted ...
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1answer
25 views

What input for a combined model (3 nets)

I have this architecture, made of 3 NNs: In code: ...
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1answer
52 views

Shared classifier for 3 neural networks (is this weights sharing?)

I would like to create 3 different VGGs with a shared classifier. Basically, each of these architectures has only the convolutions, and then I combine all the nets, with a classifier. For a better ...
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13 views

How can I Determine a Treshold According to the Precision and Recall?

I am gettin these precision and recall values from my classifier and I want to determine a treshold for the test data. How can I determine that treshold? Is these values enough or something else is ...
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1answer
22 views

Should we also include negative instance in cross-validation process of one-class classifiers?

For a one-class classifier to do text classification, only positive instances are used for training. However, in the cross-validation process to select the best hyperparameters, should we also include ...
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45 views

Algorithm to predict the best time to recall a client

Let's immagine I have a dataset of calls from a call center to clients. Each call has a lot of information like at what time it was made, duration, if it was answered or not, if the client purchased ...
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2answers
118 views

what happens when a decision tree can't be split into further unit values?

Suppose I have a dataset A B C D 1 1 1 0 1 1 0 0 1 1 0 1 1 0 1 1 Here A,B,C,D are my independent features and D is my dependent feature. Now if I make a decision ...
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1answer
32 views

Combining multiple probabilities from a classifier. Propagating probabilities

Let's say I have trained a classifier that classifies images of animals into 10 different classes. And let's say that I have 20 different images of a particular animal and because I know the ...
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1answer
34 views

Selecting a boundary on a binary classifier to optimal precision and recall

I have a logistic regression classifier that shows differing levels of performance for precision and recall at different probability boundaries as follows: The default threshold for the classifier to ...
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27 views

Validation fraction parameter of sklearn's Gradient Boosted Classifier in use with time series data

I'm looking at using sklearn's Gradient Boosting Classifier (GBC) to predict the sign of stock returns. My question is regarding the parameter "validation_fraction" used for early stopping. ...
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20 views

Inferring composition of a subset of classes of multiclass dataset

I've come across a problem in assessing the design of a Machine Learning solution I am involved in, which I will describe using a commonly known dataset, the Iris Dataset, and some drawings. Suppose ...
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1answer
127 views

XGBoost skews towards minority class

I have a dataset with 85k positive labels and 53k negative labels. For this use-case, I am trying to maximize my efforts to the negative class (accurately identify true negatives, and minimize false ...
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1answer
35 views

Dropping attributes leads to better classifier accuracy? (Titanic Set)

I am currently tackling the Titanic Dataset on Kaggle. The goal is to find a classifier that can predict whether a passenger will survive or die. The dataset has features that I believe are strongly ...
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1answer
185 views

Question about reshaping array size for KNN Classifiers

I keep trying to run a new set of data through my KNN Classifier but would recieve the message: ValueError: query data dimension must match training data dimension ...
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1answer
35 views

ANN Classifier for extracted discrete image features

I have a features extraction algorithm that works well to extract features from images. I want to develop an ANN to classify those images based on those features. I have extracted features in a csv ...
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1answer
274 views

Naive Bayes vs Full Bayes model classifiers

I have a hard time to understand when Naive Bayes works better than Full Bayes. In general, i know that naive bayes does the assumption that features are independent given the class. However, if ...
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74 views

Detecting punch type using CoreML Activity classifier

I’m trying to train an activity classifier (made by Apple) to detect with kind of punch is thrown during boxing training. Accelerations are taken directly from an Arduino Nano 33 using Bluetooth low ...
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1answer
48 views

Dicsrete values as taget variable

I have discrete values in the target variable(Exactly 13 different values in total) . When I am giving that as input to Random forest Classifier ,it gives error that input as continuous. And if I give ...
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37 views

How can I test my trained model on a completely new dataset? [duplicate]

Preface I have an annotated text dataset on hate speech. Simply put, the dataset consists of a column called text which includes a piece of text, and a column ...
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1answer
44 views

What does these points mean in Naive Bayes?

I have two concept related questions related to Naïve Bayes. Naïve Bayes is robust to irrelevant features. What does this mean? Can anyone give an example how does the irrelevant features cancels out ...
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1answer
34 views

For the line $w^Tx = 0$, how do we know the direction of the vector $w$

On page 17/28 of Lecture 3: Linear Classification, why the slope of $w$ must be positive?
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2answers
549 views

Difference between packaged sentiment analysis tools (TextBlob/NLTK) and training your own classifier?

I'm new to ML and training classifiers in practice, so I was just wondering what the difference was between the built-in sentiment tools of packages such as NLTK and TextBlob as compared to manually ...
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1answer
39 views

Attitude to text mining and preparing tokens, irrelevant words, low accuracy

For purpose of quite big project I am doing a text mining on some documents. My steps are quite common: All to lower case Tokenization Stop list and stop words Lemmatizaton Stemming Some other ...
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1answer
34 views

Classification - Divide the interval (0 - 1] to lets say 100 classes and use each class to make a calculation

class-1 represents 0.01, class-i represents 0.01*i, class-100 represents 1.00. Thus, when the classifier predicts the class-y and it should have predicted class-(y+1) there is a small error so we can ...
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1answer
41 views

Classification Model based on Ordered Features

I am trying to build a classifier for a specific card dataset let's say cards or no cards. I am using Mobilenet trained on the Imagenet dataset as my classifier and further training it on my dataset. ...
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2answers
33 views

How can I do the correlation between two estimators?

I'm working with several estimators of all kind. Then, I want to stack these estimators, and the best is if they have low correlation between them. I suppose that the correlation method depends on ...
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1answer
69 views

Building document classifier based on keywords, what would be the steps?

I have a requirement of classifying documents(.doc files) based on the profiles. I have a csv file with data: ...
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0answers
24 views

Penalization term for unfairness

I am reading [1], where the researchers do a logistic regression, but add to the loss function the following penalization term for fairness $ R^{AVD}_{FP}(\theta; S) = \left\lvert \dfrac{\sum\limits_{...
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162 views

SVM/Naive Bayesian text classification on multiple features

I was building a text classifier which takes into account certain features of the text and classifies them into two - "Yes" or "No". I have trimmed the text, removed stopwords and have applied TFIDF ...
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2answers
41 views

Certainity of a classifier

How to build a classifier that by default will predict that it is for class 1, but if the classifier believes with 80 certainity that it belongs to 0, it will be classed as 0. How to check how certain ...
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1answer
189 views

Difference in model performance measures of train and test data sets

I am using CART classification technique by dividing a dataset into train and test sets. I have been using Mis-classification error, KS by rank ordering, AUC and Gini as MPMs(model performance ...
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1answer
68 views

How to deal with name strings in large data sets for ML?

My data set contains multiple columns with first name, last name, etc. I want to use a classifier model such as Isolation Forest later. Some word embedding techniques were used for longer text ...
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3answers
251 views

Image Classification on non real images

I was wondering how image classifier networks perform on images that are not photographs. For example, if you were to feed a drawing of a car or a face to an image classifier that was only trained on ...
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3answers
467 views

How do two perceptrons produce different linear decision boundaries?

I'm trying to visualize how two perceptrons converge to two different decision boundaries (which is ultimately used to create the classifier for the non-linearly separable data). Source: https://tdb-...
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2answers
521 views

Why is my training accuracy decreasing higher degrees of polynomial features?

I am new to Machine Learning and started solving the Titanic Survivor problem on Kaggle. While solving the problem using Logistic Regression I used various models having polynomial features with ...
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0answers
30 views

Correct approach to usage of class labels in cell imaging data

As part of a group project at university, we are given a series of videos of cell cultures over a 24 hour period. A number of these cells (the "knockout" cells) have had a particular gene removed, ...
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2answers
13k views

How do I get the feature importace for a MLPClassifier?

I use the MLPClassifier from scikit learn. I have about 20 features. Is there a scikit method to get the feature importance? I found clf.feature_importances_ but it seems that it only exists for ...
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2answers
13k views

When should I use StandardScaler and when MinMaxScaler?

I have a feature vector with One-Hot-Encoded features and with continous features. How can I decide now, which data I shall scale with StandardScaler and which data scale with MinMaxScaler? I think I ...
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1answer
22 views

Converting int list to vector list

I want to train a text classifier using OnevsRestClassifier, but have problem getting a propper y. Currenly my y is a list of int, but I need it as a list of vectors. My y: ...
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2answers
105 views

Would a decision tree classifier be applicable here?

File from a situation where it is required to predict today’s stockprice from the stock prices of the previous three days: Could you use a decision tree classifier for this task? Why or why not?
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3k views

Always getting value one for a binary classifier

I'm using keras. I have one classification problem. The output should be either 0 or 1. I trained my model and I'm getting 86.59 accuracy. But when i check the predicted output what I'm seeing is all ...
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10 views

What happens if I do not encode the lables or classifiers in the data? [closed]

I have a data where the three variables are numerical and one variable is a string. I am using the simple decision tree algorithm. Read somewhere that the data in strings must be encoded with one hot ...
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3answers
5k views

How to handle "unknown" category in machine learning classification problems?

Tutorial problems come in the form of binary or mult-class classification where data are all properly labelled. In real-life applications, there are incoming data that do not belong to any category ...
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2answers
70 views

Support Vector classifier perform well with input features rather than transformed features in contrast to ANN-BP, random forest (other classifiers)

I am working on stock data with 5 raw features (OHLCV). Using few transformations used by technical analysts, have created 20 more features giving different kinds of indications. When trying to ...
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1answer
20 views

Adding the input layer - units with a decimal

I took the course Machine Learning A-Z from Udemy and am trying to apply what I learned in the tutorials. Theye taught us in the "Adding the input layer" portion of an ANN that the units is based off ...
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1answer
75 views

What can I use to post process an NLP tree generated from the python library `spaCy`?

Using spaCy as the NLP engine for a chatbot, I call nlp("Where are the apples?").print_tree() and receive: ...
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1answer
450 views

Class Imbalance Problem

I'm making a multiclassifier model with 5 classes. (it is not important in my question whether it has 2 classes or 5 classes, though). class distribution is very imbalanced. So, I did resampling for ...
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3answers
89 views

Classifier that optimizes performance on only a subset of the data?

I'm working on machine learning problem where I'm only interested in getting high accuracy within a narrow band of my predicted likelihoods. Specifically, I want an algorithm that will score very ...