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).
93
questions
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0answers
9 views
How to block a user for specific time after 3 attempts? (Java EE,Servlet) [closed]
I've created a simple login servlet in which the user enters his email and password and it checks if he's a registered user then it logs him in , if he's not it says login fail,the credentials are ...
1
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0answers
12 views
Reinforcement Learning: weights turn NaN [closed]
I'm currently implementing Q-Learning with linear function approximation for the game Snake, but I doesn't seem to get it working: the weights all eventually turn NaN and I have no idea why.
Maybe ...
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1answer
30 views
Binary Classification with OpenNLP
I'm trying to apply binary classification with OpenNLP. I could already successfully classify movies by different genres. The data sample has the form:
...
3
votes
1answer
49 views
How do I get an accurate probability when my program that tests in the millions returns significantly different results each time?
Apologies in advance, I have never (seriously) studied statistics and I'm out of my depth, so this may not be a simple question.
I wrote a program in java to determine the likelihood of a Tenhou in ...
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0answers
16 views
Finding thresholds to optimize score sum for multiple variables
This problem involves finding value thresholds for 2 variables to optimize the highest score sum.
I have a data table, with 3 columns. x, y, score. With over 1 million of rows.
x
y
score
3.0
1.0
-5
...
1
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1answer
89 views
Difference between One Rule Classifier and Decision Stump in WEKA
WEKA Explorer seems to come up with two different models for OneR (rules) and Decision stump (trees). Is has to be the underlying measure of "best split" that is different. But for a single ...
0
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1answer
64 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
45 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 ...
1
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0answers
98 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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0answers
201 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
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 ...
3
votes
1answer
181 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
180 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
vote
1answer
30 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,...
2
votes
1answer
197 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 ...
11
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3answers
2k 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.
...
0
votes
1answer
319 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 ...
0
votes
2answers
2k 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 -> ...
0
votes
1answer
171 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 ...
1
vote
2answers
1k 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'...
6
votes
2answers
1k 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
votes
1answer
274 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 ...
4
votes
2answers
7k 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 ...
1
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0answers
43 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
vote
1answer
986 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 ...
1
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0answers
33 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 ...
1
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0answers
164 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 ...
1
vote
0answers
150 views
What algorithm could be used to recommend wine given past ratings [closed]
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 ...
1
vote
2answers
2k 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) ...
1
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0answers
371 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 ...
1
vote
2answers
3k 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
vote
1answer
579 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
votes
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? ...
5
votes
2answers
7k 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
184 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
votes
1answer
557 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 ...
1
vote
2answers
874 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 ...
0
votes
1answer
372 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 ...
0
votes
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
vote
1answer
3k 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 ...
1
vote
1answer
84 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):
...
0
votes
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
votes
1answer
88 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 ...
2
votes
0answers
72 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 ...
1
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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 ...
1
vote
0answers
1k 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 ...
8
votes
3answers
17k 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), ...
3
votes
1answer
305 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 ...
0
votes
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 ...
-1
votes
1answer
116 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. ...
