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

learn more… | top users | synonyms (1)

0
votes
0answers
22 views

has anyone tried to use spectrum kernel [duplicate]

Can any one explain me how to use string kernels to quantify the similarity between short texts? thank you. regards
1
vote
0answers
12 views

Meaning of “reconstruction error” in PCA and LDA

I am implementing PCA, LDA, and Naive Bayes, for compression and classification respectively (implementing both an LDA for compression and classification). I have the code written and everything ...
0
votes
1answer
16 views

Computing the Interaction gain. Is there an Error in the infotheo package in R?

In order to implementing a certain feature selection method for a classification problem I need to estimate the the interaction the interaction gain between two features and the target variable which ...
2
votes
0answers
15 views

Is dimensional reduction using Autoencoders possible with a small sample size?

I have a data set that is not too big but high dimensional, let say 10000 dimensional. I want to use an autoencoder to extract relevant features (clusters) in the data. Usually when I have seen ...
0
votes
0answers
16 views

What does make SVM a “soft computing” method?

Soft computing is defined in [1] by the capability of "operating with uncertain, imprecise and incomplete information in a manner that reflects human thinking". So, based on my limited understanding, ...
0
votes
2answers
23 views

Dynamical time warping for dynamical system classification

I am trying to find a way to classify and segment a large set of time series that each individually describe a dynamical system. I wanted to know if the following idea for doing so is a feasible ...
0
votes
0answers
9 views

model to learn graph

I'm looking for machine learning techniques which allow me to obtain a model learning relationship of graphs. In a basic regression problem, model learns a relationship between real values. A model ...
0
votes
0answers
8 views

AdaBoost - How to use the distribution D [migrated]

I am trying to implement AdaBoost algorithm in Python. I have m weak classifiers in list called classifiers. I have vector _D ...
-1
votes
1answer
19 views

clustering evaluation for a special case

In my dataset each point comes from one of 3 classes, so the true labels are like [0,1,0,0,0,2,1....]. I have to cluster them in 200 clusters. I want each cluster ...
1
vote
0answers
9 views

Sequence analysis with multiple sequences

I would like to recognize different states in a sequence of multiple vectors. To make it little more clear, here is an example: I have 2 (or more) vectors in a sequence: head position(HP) and eye ...
0
votes
0answers
14 views

Calculate state change probability

I am having telco order management data and need to calculate the probability of each order going through different stages. data is like this: Order No; product_type; time spent in step1; time ...
0
votes
3answers
56 views

Why do we do hypothesis testing on estimates of linear regression?

I was reading about linear regression and what I understood is that once we minimize OLS equation we get the beta parameters. Its just like solving a normal equation to get the unknowns. Then why do ...
1
vote
0answers
18 views

Relation between precision, recall and sample size

I have a large data set for binary classification problem. Now in order to fit model to data I have been trying modeling using various sample size. For each sample size I gets a different precision ...
18
votes
3answers
1k views

In machine learning, why are superscripts used instead of subscripts?

I'm taking Andrew Ng's course on Machine Learning through Coursera. For equations, superscripts are used instead of subscripts. For example, in the following equation $x^{(i)}$ is used instead of ...
0
votes
0answers
12 views

SMOTE algorithm how to select over and under percentage?

I have a highly unbalanced binary dependent variable (i.e. cases of '1' is <5%). I am trying to implement SMOTE algorithm using R DMwR package. I wonder in general, how we determine the parameters ...
0
votes
0answers
36 views

Confused Scikit results

I am doing classification machine learning on a particular dataset on which an SVM model (using Scikit.learn) is giving a Matthew's correlation coefficient (MCC) of ...
0
votes
0answers
16 views

Suggestions for Neural Network Structure for Time-Series prediction with constant covariates

I've been working on a time series prediction problem and wondered if someone has run across a similar problem structure & can make a suggestion on how to structure the training data, network, or ...
1
vote
0answers
39 views

Which machine learning technique is appropriate for my problem?

I'm new in machine learning topics and I've problem in modeling my environment which has multi parameters with different value ranges and a few actions to perform when value of each parameter is not ...
2
votes
0answers
27 views

How to correctly build a training/validation/test?

I have a database that is comprised of 3 sets of data. The first created in office conditions, the second in the same office taken on different day and the third drawn from random images from the ...
0
votes
0answers
12 views

How to do multi-labelling regression in machine learning?

There are a few links available to do multi-label classification (not to be confused with multi-class). But how to do multi-label regression given a highly non-linear real-valued data set? My ...
0
votes
0answers
8 views

Feature scaling when using Rectified Linear Units [duplicate]

Is it necessary to scale the input data of a Neural Network to a certain range (e.g. 0 to a big number) if the activation function consists of ReLus?
0
votes
0answers
22 views

Normalization after PCA Whitening (for Deep Learning)

When training a Deep Learning model like an auto-encoder, is it necessary to normalize data again after it has been processed by PCA Whitening? Right now I zero-mean my data before PCA and use the ...
2
votes
0answers
20 views

Converting between different accuracy/error metrics

I am trying to compare model accuracy between several different measurement metrics. For example, some citations use accuracy while other use error. That one is rather obvious, but there are lots of ...
1
vote
0answers
30 views

How do I get initial transition matrix probabilities?

I have to develop a system to detect and prevent bank transactions fraud - just credit card transactions, for simplicity - I'm thinking about using markov chain. How would I get the initial ...
0
votes
0answers
25 views

Terminology clarification: Discrete distribution == Categorical distribution?

I'm reading "The Indian Buffet Process: An Introduction and Review" by Griffiths and Ghahramani and wanted to confirm my understanding of one of the terms they use. On page 1188, they say that the ...
0
votes
0answers
17 views

How do I reduce number of features without rebuilding the model?

I'm pretty new to ML/NLP thus my question maybe naive. How do I reduce number of features without rebuilding the model for Naive Bayes Classification? I'm using MALLET to build the model to classify ...
0
votes
0answers
10 views

Mixture of experts learning with unlabeled data and a fitness function

I have a classification problem. It essentially amounts to sorting a large number of integer vectors into a small number of categories. The samples are completely unlabeled, and even I do not know how ...
2
votes
1answer
24 views

Levels of “hyperparameterization” in Hierarchical Modeling

Suppose we have observations $y$ that we wish to model as having being randomly sampled from a distribution with parameter $\theta$. General Bayesian approach assumes a prior distribution over ...
0
votes
0answers
6 views

Implementing a model for 'Flash Fill'

MS Excel (since 2013) offers a Flash Fill feature that learns how you want to transform columns in your spread sheet based on training data for some rows and then applies this transformation on all ...
0
votes
0answers
21 views

Chinese restaurant/Dirichlet process get the hyperparameters from already clustered data

Imagine I have already some N clusters (or filled tables in CRP terminology), is there a way to estimate the hyperparameters alpha, theta (wiki terminology ...
0
votes
2answers
32 views

How to calculate distance between points in DBSCAN matrix data?

I'm making a simple C implementation of DBSCAN following his pseudocode. If I well underand how DBSCAN works, I may represent my set of N elements (each with M features) with a NxM matrix. When it ...
0
votes
0answers
19 views

Impact of data distribution on (statistical/ machine) learning performance: overview

I am trying to get a global view on the different ways how (non-ideal, messy) data distributions can affect different performance dimensions of statistical/machine learners, incl. but not limited to: ...
0
votes
1answer
35 views

Overfitting and Data splitting [on hold]

Let's say that I have a data file like: Index,product_buying_date,col1,col2 0,2013-01-16,34,Jack 1,2013-01-12,43,Molly 2,2013-01-21,21,Adam 3,2014-01-09,54,Peirce 4,2014-01-17,38,Goldberg ...
1
vote
1answer
88 views

Machine learning on dummy variables

I have a dataset on which there are about 1000 dummy variables indicating location. I do not have access to lat/long. I am using xgboost to train it. The more that I train it does seem to be lowering ...
0
votes
0answers
42 views

How to boost the performance of support vector machine?

I have 4 different data samples: Stage 1: [152 X 27578] Stage 2: [48 X 27578] Stage 3: [48 X 27578] Cancer: [63 X 27578] Each sample are the different stage of cancer in descending order. Here I ...
0
votes
0answers
24 views

Reasonable R² for a Machine Learning Problem [on hold]

I got a R² of 3.6 in a competition of Machine Learning which were not disclosed meanings of variables. I am using XGBoost method. Is this number unacceptable for this type of problem or may have ...
1
vote
0answers
17 views

Select and weigh questions on a reading assessment

I am a phd student in computer science and as such I am the goto guy for anything "mathy" in the cross discipline research group to which I belong. I have recently been given an assignment at work I'm ...
0
votes
0answers
7 views

Finding feature values most specific for a subset

I have a set of items with lots of categorical features. I also have a small subset of this set. I want to find out what's different about this subset compared to general population (i.e. what feature ...
1
vote
0answers
52 views

xgboost binary logistic regression

I am having problems running logistic regression with xgboost that can be summarized on the following example. Lets assume I have a very simple dataframe with two predictors and one target variable: ...
0
votes
0answers
24 views

Machine learning for detecting bank transactions fraud [on hold]

I have to develop, as much as I can, a bank transactions fraud detection system in under 5 months. Im using complex events processing, and as I see it I have to implement, firstly, a system that ...
0
votes
0answers
10 views

Difference between Nearest Neighbour and Nearest Centroid

I'm trying to understand the difference between Nearest neighbour classifiers and Nearest centroid classifier. Using the nearest neighbour, one selects a data point ...
0
votes
1answer
28 views

Need guidance on image classification problem with large feature matrix

So I've got an interesting problem that I'm struggling with and I wanted to hear some ideas on possible solutions. The data is not public and I can't go into much detail. The problem involves a ...
0
votes
0answers
18 views

Application fields of Neural Network and backpropagation algorithm - frontiers of Artificial Intelligente

I am studying some neural networks and, as far as I understood, the backpropagation algorithm is one of the fundamental learning algorithm. Up to now I have encountered that this algorith is applied ...
0
votes
1answer
26 views

Grouping usernames/emails in a data set

I have a column in a dataset that is the 'user'. Can look like this: tom green tgreen tomgreen@here.com sam blue samtha green How do i get this to group this so that the first three are grouped ...
0
votes
0answers
39 views

Outer product approximation of the Hessian

On p251 of Bishop's machine learning book, the Hessian for least squares is derived (as a preliminary step to the outer product approximation): $ E = \frac{1}{2} \sum_{n=1}^{N} \left(y_n - ...
0
votes
0answers
35 views

Deep Learning Framework for noobs [closed]

I need a suggestion. I am completely new to ML, what deep learning framework should I use at this point. My main requirement is that it should have a large enough community that tolerates noob ...
0
votes
0answers
11 views

Choice of Boltzmann Exponent for Simulated Annealing

I was wondering if there was a good source on the optimiality of different choices for the "Boltzmann Exponent" for Simulated Annealing. Mathematica defines it here, though it would generally apply to ...
0
votes
0answers
23 views

Boosting the prediction results in machine learning

I am having the datasets of 152 samples and 151 features.I implemented libSVM algorithm as a classifier. I am getting a classification accuracy just above 55% Is there any way I can boost my ...
1
vote
0answers
25 views

Machine Learning for Motion Capturing

What kind of machine learning techniques are usually used to keep track of the markers? In motion capturing, one usually puts so-called markers onto a person moving (which can be seen here), and ...
0
votes
0answers
23 views

Pre-processing (center + scale, box-cox transformation) inside cross-validation?

I have extracted features and I have now a matrix where the rows are the data points and the columns are the features. Of course, I have to center and scale (zero mean and unit variance) each feature ...