Methods and principles of building "computer systems that automatically improve with experience."

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deep learning in mobile apps [closed]

Can deep learning be applied in mobile apps, and if possible how? Is it possible ? to deep learning needs more computational cost? how can we minimize the computational cost for deep learning on ...
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39 views

What's an intuitive explanation for why MAP is variant under parameterization?

I understand why MAP is variant under parameterization mathematically, but I don't really understand it intuitively. To help me out, my professor gave me an example where reparameterizing MAP ...
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3 views

How does Weka chiSquaredAttributeEval generates single attribute selection list while Chi Square itself is class based?

I have implemented my own Chi-Square ranker in C# however the example i found on the internet shows that Chi-Square ranks the each attribute within its class However Weka generates attributes as a ...
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34 views

Attribute weighted KMeans

I'm trying to use Kmeans clustering, with an intent to find out clusters by weighting the attributes. Eg. if attribute A matters less than attribute B then the output should put more weight on ...
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41 views

What model to use for predicting future expenses of an individual?

I am currently working on a Personal Finance application, which tracks expenses of a person. When entering an expense entry, the user selects the category of the transaction (e.g. 'Bills', 'Food', ...
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4 views

Activation of different states in a neural network

hello i want to ask if it is possible to create a neural network in mat lab that is able to have at least 4 states (by states mean something happening parallely not the output )which gets activated ...
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12 views

Queries regarding 'logistftest' function of logistf package for model comparison

I am a user of r package ‘logistf’, I have 2 queries regarding the ‘logistftest’ function when doing model comparisons, I would appreciate if anyone can give helps. I am comparing two models (one ...
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28 views

Are there better algorithms than Convolutional Neural Networks?

I was wondering if there are any better algorithm/paradigm than Convolutional Neural Networks for tasks related to images ? Whichever problem domain I have picked up (Image classification, scene ...
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26 views

Understanding LDA inference

It is said that the key inferential problem that needs to be solved to use LDA (latent dirichlet allocation) is that of computing the posterior distribution $p(\theta,z | w, \alpha ,\beta)$. I know ...
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26 views

Neural Net Matrix Multiplication

I'm trying to figure out the matrix multiplications for the implementation of a single hidden layer neural net for MNIST digit recognition in Python. Like the following: ...
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7 views

Auto-association with backpropagation and hopfield network

When I was studying back propagation the professor mentioned that we could use auto associative memory to extract some information, but it seems that the Hopfield network (recurrent network) is better ...
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33 views

Word-topic matrix in Latent Dirichlet Allocation

In the Latend Dirichllet Allocation model described in Wikipedia (https://en.wikipedia.org/wiki/Latent_Dirichlet_allocation), is $\beta$ the word-topic matrix? I understand that $\beta$ is the ...
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27 views

Selecting ARIMA Order using Rolling Forecast

I'm wondering if a rolling forecast technique like the ones mentioned in Rob Hyndman's blogs, and the example below, could be used to select the order for an ARIMA model? In the examples I've looked ...
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16 views

Difference between rulefit and random forest

I'm trying to understand the difference between these a bit better. I understand pretty well how random forests work but I guess I'm more hazy on rulefit and how exactly it's different. I know rulefit ...
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2answers
44 views

One-vs-many/One-vs-all - what value to use as probability?

I have constructed SVMs to do a one-vs-many approach to classification. Let's say I have 3 classes and I train 3 SVMs in a one-vs-many format. This gives me 3 SVMs each trained positively on one of a ...
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13 views

How effective is connectionist temporal classification on a small dataset of 30 hour audio? [closed]

I am performing speech recognition on my local language and this seemed to be a scalable solution. Please provide suggestions
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17 views

Limited-memory BFGS and MaxEnt Models

According to Wikipedia, "L-BFGS has been called 'the algorithm of choice' for fitting log-linear (MaxEnt) models", however I'm having trouble finding a good reference to show how incorporating the ...
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24 views

Feature selection step before decision tree?

I want to use rpart (a R package) to build a decision tree model. The data is a high-dimensional expression matrix, with ~50,000 predictors and ~500 samples. The response is a categorical variable. ...
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9 views

What's the value of f1 score when true positives are zero? [duplicate]

f1 score is defined as F1 = 2 * (precision * recall) / (precision + recall) However if true positives are zero, this gives 0/0. How to deal with this scenario?
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20 views

How do we do predictive lead scoring in R? [closed]

Assume my historical data contains(Region,Industry,No.of.Days,Revenue of the company,whether the deal was closed or not) i.e., data of a sales lead. I am concerned about predicting a lead score for ...
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13 views

Finding a number that considers %worse outcomes and %better outcomes

I have a baseline algorithm and lots of test algorithms. The baseline algorithm's performance is compared to every other algorithm. What I'm left with is a table like so: ...
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13 views

Comparing algorithms: runtime vs accuracy

I am comparing several algorithms with respect to their runtime and accuracy on several datasets. I follow [1] and compute the average rank using the accuracy and apply the Friedman and Nemenyi tests. ...
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1answer
66 views

What is principal subspace in probabilistic PCA?

if $X$ is observed data matrix and $Y$ is latent variable then $$X=WY+\mu+\epsilon$$ Where $\mu$ is the mean of observed data, and $\epsilon$ is the Gaussian error/noise in data, and $W$ is called ...
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17 views

Classification on sequential data

Context: I am working on a classification project where I recommend items to customers based on their past purchase history. Question: How will "time leakage" affect training? Example: Let's say ...
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29 views

Machine learning step order question

I have been working on this project for over a year now and I believe i finally have things figured out. Mainly i'm looking for any suggestions or things i'm doing wrong with my process, but i also ...
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35 views

A question on conditional gaussian distribution

The book on Pattern Recognition (by Bishop) begins the section on conditional gaussian by saying: An important property of the multivariate Gaussian distribution is that if two sets of variables ...
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18 views

kPCA with RBF Kernel and Circle data [on hold]

When applying Kpca with RBF kernel to a circle data, the projection onto the first eigenvector gives the same value (all points have the same projection value). I don't understand why since kPCA is a ...
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49 views

In machine learning, Is it better to have class ratios balanced or representative of the population?

In the context of machine learning, let's say you have a problem in which classes in the real population are not balanced - eg Class A occurs 80% of the time and Class B occurs 20% of the time. In ...
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1answer
13 views

Machine learning algorithm for predicting 'action' performances

I'm given: the current state of the system S, for which the objective function C can be calculated. There's also a set of possible actions a1, a2, .... . Each action leads to a change in the state. ...
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5 views

Training a binary LSTM classifier with few true positives

I'm trying to solve a multilabel classification problem with n-binary LSTM classifiers. I have 17 classes in total, where multiple classes may be true for each example (e.g. news articles with ...
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20 views

Name of parsing and recognition problem

I have millions of user generated document that contain smartphone specifications. I want to get certain properties from those documents, e.g: OS, display resolution, processor, RAM, camera ...
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1answer
58 views

Noob Data Design Question - 1 on 1 competition

My question is about how to best structure my dataset for a competition between 2 players of a game (for the purposes of prediction of future game winners). There will potentially be hundreds of ...
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1answer
21 views

hyper parameter optimization grid search issues

I keep running into the same problem while doing a grid search to optimize the C and gamma parameters of an SVC. Every time i do the grid search, the best values seem to occur at around C = 100000 ...
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9 views

timeseries forecasting when datapoints doesn't start at same time period

I have a dataset which has lifecycle information of different products but all the products doesn't start selling in same period or same year/quarter.In this case how should i do time series modelling ...
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16 views

How well should backpropagation agree with finite difference methods when calculating derivatives of the error function?

I have attempted to write a Neural Network code, and it was suggested in my textbook (Bishop - Pattern Recognition & Machine Learning) that a very useful debugging technique is to check your ...
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18 views

how to check if model built is valid or outdated for new data

If i have a classification or clustering model built for retail customers till last year.How do i check if my model is still valid to this year's data? We can check accuracy of model to new data but ...
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13 views

handling dataset if some columns have sparse data

1)if in a dataset 8 columns and of them 3 columns have sparse data[lots of missing values].can anyone tell me what are the general practices followed to transform this data before modelling. I know we ...
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10 views

Genetic programming for a function of functions of inputs

Given a vector of variables $X=(x_1, x_2, ..., x_n)$ I have previously used genetic programming for deriving an expression for a function $y=f(X)$ from a training dataset of tuples $<X, y>$. ...
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10 views

Conditional probability sub-model so solve setting with a factor that has many levels

I stumbled upon a post of the http://www.win-vector.com/ blog where they treat the problem when a factor with many levels occurs. In my understanding instead of using the factor itself, they use the ...
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21 views

How to Choose Activation Functions in a Regression Neural Network?

I'm having difficulties with some basics regarding the application of feed forward neural networks for regression. To be specific, lets say that I have an input variable $x \in \mathbb R^4$ and data ...
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13 views

A quantity is normally distributed with a mean of $t|y(x,\mathbf{w})$. [duplicate]

Let $y = \displaystyle\sum_{i=0}^Nw_ix^i$ be a polynomial fit curve. In this question, we are looking at this curve from a probabilistic perspective, as Bishop says, towards a full Bayesian treatment. ...
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9 views

Package Arules with a twist: duplicated items in each transaction

I am interested to work on this: For arules package in r, we could find what's most likely purchased within 1 market basket as referred to ...
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1answer
15 views

Different fonts of audio from a single audio source

I know that is a duplicated question. But there is no answer for the original one and I want something more specific. On original question, the user Caaarlos wants the interpret different fonts of ...
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Question on Bayesian Curve fitting (Pattern Recognition and Machine Learning by Bishop) [closed]

Let $y = \displaystyle\sum_{i=0}^Nw_ix^i$ be a polynomial fit curve. In this question, we are looking at this curve from a probabilistic perspective, as Bishop says, towards a full Bayesian treatment. ...
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11 views

Mahout Item Recommender score for every combination of user and item

We're looking to create a recommender using Mahout that will generate a recommendation score for every combination of user and item based on a users rating of items. The number of items is fairly ...
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7 views

Detecting images inside website snapshots and extracting them with machine learning

I was wondering if I could detect images inside website snapshots and cut them out of the snapshot. for example I can download Image Snapshots from any website via PhantomJS. this gives me a ...
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15 views

Two ways of defining a squared kernel: are they equal?

Let's say I have a PDS kernel $K$, and a corresponding featuremap $\psi(x)$. I am interested in vectors in the RKHS / featurespace of $K$ with limited norm, the norm is limited by $\Lambda$. Now I ...
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74 views

Generate code for sklearn's GradientBoostingClassifier

I want to generate code (Python for now, but ultimately C) from a trained gradient boosted classifier (from sklearn). As far as I understand it, the model takes an initial predictor, and then adds ...
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12 views

Is this problem Multiclass or MultiLabel?

I am working on a coursework that asks me to take an image and classify it in one of the 15 scenes. An image can be only 1 class at a time. So that makes it a multiclass problem right? How could one ...
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25 views

Outliers detections in time-series

I am searching algorithms for detecting outliers in a time-series data. I see that there are a lot of algorithms and they have an implementation in R. But i don't find any explanation on how they ...