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Questions tagged [java]

Java is an object-oriented language and runtime environment (JRE). Java programs are compiled to bytecode and run in a virtual machine (JVM).

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1answer
32 views

What does this ROC value mean?

What does this roc value mean? How do I interpret it? Are there values which help in inferring it like in case of kappa?
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0answers
19 views

Find roots of regression function

Physical problem: Signal data comes from several sensors (e.g. 4) and there is empirical knowledge, that data of one of them (e.g. "productivity") depends on other data. Signals of other sensors could ...
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0answers
38 views

How to determine if my data is discrete or continuous in java? [duplicate]

Could you mind to teach me how can I test whether the given data is discrete or continuous in java? For example, given array (98.6, 99.2, 103.1) and my statistic service should determine the data ...
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1answer
126 views

How to compute k-means on provided inverted index using tf-idf

I built an inverted index to represent the following sample documents: ...
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0answers
15 views

What does the OffsetConjunction method in the MALLET machine learning toolkit do?

Anyone having built sequence learning models using the MALLET toolkit and had used the OffsetConjunction method for features, could kindly provide an idea of what the method does exactly. An example ...
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0answers
129 views

What is a good percentage value for SMOTE in Weka

I am using the oversampling technique named as SMOTE to balance my dataset in Weka. To balance my dataset I needed to use 1300 as my -p (percentage) value. The default -p (percentage) value is 100. ...
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0answers
579 views

Why does my training loss decrease initially, but subsequently increase?

I do understand that this has something to do with the learning rate, but I just can't think of any reasonable explanation as to why training loss would continue to increase rapidly. Here is my ...
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0answers
17 views

Manipulating large data frames - speed issue [closed]

I'm dealing with a lot of data in R and I've run into problems with its computational speed. I have hundreds of lists of data frames. Each list is composed of 100 data frames. Each data frame ...
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0answers
55 views

Neural Network for Rain Prediction - Only Learning Averages [duplicate]

I'm attempting to create a Neural Network to use as a rain model to generate representative precipitation levels for a given location. The problem I'm facing is that the network always converges to ...
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1answer
177 views

Could this be classed as machine learning? [closed]

I did a little Google Search on machine learning and got this: Machine learning is the ability of a system to learn without being explicitly programmed. So I decided to attempt to do this on java. ...
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0answers
145 views

Nonlinear dimensionality reduction in Java/on JVM

Is there a (decently) fast implementation of Manifold Learning algorithms on JVM? I tried Smile library but it takes dozen minutes to run its Isomap on my computer, while scikit-learn ...
1
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1answer
27 views

Similiarity between temperature vectors [closed]

Please help in the following problem: I have a set of data consisting of daily temperatures, gathered every hour, togheter with daily energy consumption. Given the temperature forecast on the next day,...
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1answer
62 views

How to sample from discrete 3D distribution

I am trying to implement a particle filter to track multiple objects. During the propagation phase I need to take N samples from a three dimensional probability distribution, which does not fit known ...
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3answers
587 views

PCA too slow when both n,p are large: Alternatives?

Problem Setup I have data points (images) of high dimension (4096), which I'm trying to visualize in 2D. To this end, I'm using t-sne in a manner similar to the following example code by Karpathy. ...
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1answer
201 views

Locating outliers in property sales data set

I have read the suggested questions that "may already have (my) answer," but don't feel they address my issue. I am not versed in statistics, so a bit more explanation to me may be necessary. I am ...
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2answers
1k views

Weka - random forrest always predicts the same class

I am classifying Portuguese tweets in to three classes, news, noise and relevant. I have used the weka gui to identify a classifying pipeline that gave good results. STWV -> Attribute Selection -> ...
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1answer
141 views

Neural network failing to add [closed]

I don't know what I'm doing wrong. I'm using DL4J, and I took their XorExample class (which trains a feed-forward network to perform xor) and tried to modify it to multiply two inputs between 0 and 1 ...
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2answers
605 views

Clustering short strings to find similar strings within a dataset

I have a large dataset (ranging from 10k to 100k items) and some of them are almost duplicates. What I'd like to do is to merge those almost duplicates by finding clusters of words in my dataset. I'...
5
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1answer
784 views

Unsupervised outlier detection in 2D space

Problem I'm working on a school project in Java and my goal is to detect and remove outliers from a dataset containin geo points. The final result should be a single cluster, with any shape, ...
2
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1answer
233 views

CNN pooling and convolution

In the past, I've worked with the MNIST dataset and I am currently working with Java. I do not use any external libraries like numpy (for python) or something like that. I started from scratch and ...
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2answers
3k views

How to use Kullback-leibler divergence if mean and standard deviation of of two Gaussian Distribution is provided?

With Apache Spark MLLib library I am trying to find Clusters within a dataset by using Gaussian Mixture Model (number cluster =3) . Now it returns 3 different values of mean and standard deviation. I ...
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0answers
33 views

Neural Network probabilities converging to biases

I'm creating an Android app which can use a variety of classification formula, and while I have normal Softmax done correctly, I keep having an issue with the Softmax Neural Network. After about 10 ...
1
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1answer
849 views

MNIST Softmax regression hitting a wall at 70% accuracy

I've implemented a Softmax regression algorithm in java as part of an Android machine learning program. However, no matter how long I let it run for, the accuracy gets to about 70.5% and then plateaus ...
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0answers
31 views

Neural network fails to capture 2D shape possibly due to biases

I am attempting to develop a Neural Network that I can generalize to several different applications. As part of this, I am attempting to verify that my Neural Network works properly on a simple ...
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0answers
160 views

Improving the results coming from an image recognition API

We are developing a software application that will automatically suggest tags (keywords) for images that are being uploaded into a database of already-tagged (by a human) images. We are using a 3rd ...
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0answers
138 views

What algorithm could be used to recommend wine given past ratings

Description: given a user's history of 'likes', I would like to predict what product should I recommend to the user, based on past likes (content based). The idea is very similar to Pandora, except ...
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2answers
1k views

How are the values of residuals (white noise) calculated in ARMA model?

I am trying to implement ARMA model in Java. I have trouble with calculating residuals (white noise) in Moving average part of the model. From the answer on this question (Fitted values of ARMA model) ...
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0answers
316 views

How to reduce dataset for plotting

I have a large dataset that contains a lot of noise that I would like to eliminate in order to reduce the size of the dataset and speed up data visualization. I was thinking to reduce the number of ...
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2answers
2k views

Calculating gradient of a function for optimization

I need to optimize a function. This function is a likelihood function which takes a set of parameters (to be optimized) and calculates the likelihood (to be optimized) as a result. ...
1
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1answer
510 views

Train neural network for forecasting

I am trying to use time series neural network to predict future values. I have time series data from 2010-2014 and I need to predict the values from 2015-2020 using time series neural network. I am ...
2
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1answer
3k views

Need guidance in image classification

I'm new to machine learning and need some help. I need image classification to tell if an image is a car or not. Is there any working example or guidance or a book for this particular question? ...
2
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2answers
5k views

How does one extract the final equation from glm poisson model?

I have a Poisson model that is performing well. Now we need to put it into Java code and release it to the world. What is the equation that I plug the Poisson coefficients into? Similar to this ...
2
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0answers
158 views

Statistical graphical models in practice

I've followed the probabilistic graphical models course in coursera and now I would like to apply what I've learnt with real data. I want to implement LDA on a large corpus of text and I was ...
2
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1answer
549 views

Which library is the easiest to start with for Deep Learning

I am quite proficient with Machine Learning libraries and now want to get into Deep Learning. I am even quite comfortable with neural networks as far as understanding back propagation algorithm is ...
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2answers
828 views

difference between stochastic gradient descent and batch

I've watched the canonical Andrew Ng video on the subject but I'm trying to translate those concepts into java, and I'm not quite sure I did it right. The thing that's confusing me is, I made a toy ...
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1answer
318 views

Java and R: Least Squares Coefficient Estimation - Start at time Zero?

This is the data set I have: vector <- c( -7.459981, 13.26651, 12.10128, 2.380662, 26.42393) Doing an estimation of the coefficient with a linear regression ...
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1answer
2k views

JFreeChart Boxplot appearance

I'm need to create boxplots to analyse and evaluate test results. Since I program in Java this answer convinced me to use JFreeChart. The BoxAndWhisker chart seemed similar to what I wanted. I spent ...
1
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1answer
2k views

One-Max fitness function (Java) [closed]

Whilst searching on Google about Genetic Algorithms, I came across OneMax Problem, my search showed that this is one of the very first problem that the Genetic Algorithm was applied to. However, I am ...
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1answer
64 views

Collective randomness of data generated using different seeds

We are generating 5 random numbers for every object we process - this is Java, but the code is pretty easy to follow (docs): ...
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1answer
2k views

Weka java API: Attribute Selection and Cross Validation

Is there a way to perform Attirbute selection(aka feature selection) (regardless of method) only for the training dataset before passing data for Cross Validation ? I currently think that the only ...
0
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1answer
80 views

Statistical Commute Analysis in Java

I have a rather large commute every day - it ranges between about an hour and about an hour and half of driving. I have been tracking my driving times, and want to continue to do so. I am capturing ...
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0answers
70 views

Graphing the usage of legal precedents

I would like to hear recommendations on what tools to use to graph the usage of precedents in a legal court in Brazil. The data is searchable at www.stj.jus.br/SCON/, and in the most recent collegiate ...
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0answers
1k views

generate frequency distribution from database

In a MySQL database there's a table with a single numeric value column. I want to plot the distribution of these values as a bar chart/histogram with the following ...
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0answers
986 views

J48 Handling Missing Value with Tree based Imputation

Aloha, currently i have some trouble and question zu implement some kind of special missing value handling in WEKA J48 algorithm using WEKA JAVA API. I want to test the performance of SHAPIRO ...
9
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3answers
15k views

Complete machine learning library for Java/Scala [closed]

Python is plenty of ML libraries (like the great scikit-learn). Is there any good for java/scala, containing many algos (regression, classification, clustering, cross-validation, feature processing), ...
2
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1answer
298 views

Predictive Modeler: How can learning Python and/or Java benefit me?

On a daily basis, I build predictive models (namely, logistic regression and credit scorecard models) using fairly large datasets (typically ~500k records and ~1k candidate variables) to predict ...
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2answers
2k views

Latent Dirichlet Allocation as input for WEKA

I am using the Weka API for my research about document classification. I wish to apply Latent Dirichelet Allocation on my dataset followed by using a classifier in Weka. However, it is not so clear to ...
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1answer
98 views

Converting FuzzykMeans to SphericalFuzzyKMeans? [closed]

I grabbed an implementation of FuzzyKMeans (FuzzyCMeans) from the nightly build of the Apache Commons Math library, but I now realize I need to use Cosine Similarity instead of the Euclidean Distance. ...
1
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1answer
896 views

how to add instances data into test arff file with the same attribute and relation with training file [closed]

I have training arff file, and also I have instances data at hand. Now I want to add the instances data onto another file, called test file, and this test file has the same relation header and ...
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1answer
2k views

Compute p-value of single value in arbitrary distribution (using java and apache.commons.math3)

I want to compute the p-value of a single numeric value drawn from an arbirtary distribution. The p-value should be comparable to p-values that have been computed with single distinict values drawn ...