MATLAB is a high-level language and interactive programming environment developed by MathWorks. It is the foundation for a number of other tools related to statistical analysis, including Statistics Toolbox, Optimization Toolbox, Curve Fitting Toolbox and Neural Network Toolbox.

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Decision Level Fusion of SVR outputs

I have two sets of features predicting the same outputs. But instead of training everything at once, I would like to train them separately and fuse the decisions. In SVM classification, we can take ...
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1answer
21 views

Digging deeper into the FitDist function

I am using the script allfitdist to find which distribution best fits my data according to the tests included (BIC, AIK etc...) - these all stem from the script ...
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1answer
32 views

Conceptual issues in AR model representation

Q1 : I am looking for a $k$ lagged (k order) AR model where k >2 conveniently k >20. I am unable to find any large AR model other than the popular second order AR model, $x_t = 0.195x_{t-1} - ...
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12 views

Probability of outputs of binary classification in MATLAB

I have a binary classification problem and using neural network and SVM for it. So I choose a threshold (for instance, 0.5) for output of neural network. If output is greater than 0.5 it belongs to ...
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9 views

Animating circle to increase and decrease in size over a period of time - matlab [migrated]

I would like to create a simple visualization whereby the circle (country) will increase/decrease in size(Base on the variables) with respect to time. How can it be done on matlab with my current ...
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17 views

Plotting a comet like animation for multiple variables

I am trying to code a visualization with 4 variables ( Carbon emission, Energy consumption, population and year) The data set i have collected so far looks like this With C1990 representing Carbon ...
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19 views

Plotting more than three variables in matlab

I am here to seek opinion on how should i represent my data that i have collected. I am to create a presentation focusing on environment. I was told that a simple bar chart and a line graph is a bad ...
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14 views

Time series forex data comparison, can someone explain the Johnansen cointegration results and their significance?

I am comparatively new to the Johansen cointegration test(new to everything of this level). I am trying to validate a model I have created based on simple statistics such as: Mean, Standard deviation ...
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25 views

Performance comparsion study on real data in MATLAB (machine learning)

I need to compare performance using 2-class classifiers–an LDA classifier and Exact Bayes in MATLAB. I have to use this dataset. Can anyone give me any advice how to do that (at least the steps of the ...
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1answer
21 views

Is it OK to increase validation checks and decrease min gradient while training neural network?

My input vector is a 130*85 matrix and my target vector is 130*26 matrix. I am using the below parameters for training the network with 60 hidden nodes. ...
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39 views

HOW TO DRAW SCATTER GRAPH FOR MY CLUSTERING OUTPUT [closed]

num = data(a1(k1):b1(k1),3); CE=0;SX=0;DM=[]; m=mean(num); %mean value calculation S=nanstd(num); DI=pdist2(num,m,'seuclidean',S); sn=size(DI); nmin=2*100/2; dmax=max(DI); ...
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14 views

How can I interpret the results of LSA?

I implemented LSA on MATLAB. I have a $D\times N$ term-document matrix, where $D$: # of words, $N$: # of docs. I did low-rank approximation using SVD, and got $$X_k = U_k \cdot S_k \cdot V_k' ...
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19 views

What Gaussian process covariance function captures an affine mean?

In the documentation for GPML, the author trained a GP with an affine mean function and isotropic squared exponential covariance function. Then there is an exercise to the reader: Try training a ...
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1answer
31 views

What is Precision-Recall Curve?

I have a data mining assignment where I make a content-based image retrieval system. I have 20 images of 5 animals. So in total 100 images. My system returns the 10 most relevant images to an input ...
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1answer
34 views

Classification Accuracy

I am classifying text based on news headlines and I am achieving accuracy up to approx 80%. I want to improve it more. But issue is that when I calculate the same with synonyms using the code below: ...
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1answer
15 views

clustering of singular values

let us consider following graph of singular values i want to make some kind of clustering of these data,namely to seperate main components from non main components,let say signal components ...
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12 views

libsvm grid search on Parallel Computing Toolbox Matlab

I am using the following code for grid search on libsvm: ...
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1answer
53 views

I want to learn about ROC curve — what is the canonical textbook?

I want to learn about Receiver-Operator-Characteristic curves, and metrics. I have read through online webpages with some basics, and I have used MATLAB built-ins to create ROC plots. It tells me ...
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1answer
35 views

Performing hierarchical clustering on a large data set

I have been applying complete linkage on about 5,000 points using matlab with no problem. I want to extend this method to much more elements. It would take me a long time to process my data to test ...
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23 views

MATLAB: leave-one-out-cross-validation for PCA

I'm trying to write my own function for PCA (of course there's a lot already written but I'm just interested in implementing stuff by myself). The main problem I encountered is the cross-validation ...
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19 views

Parameter tuning in lars (lasso) matlab

I am trying to use lars (matlab implementation:http://www.ece.ubc.ca/~xiaohuic/code/LARS/LARS.htm). I want to do a leave one out cross validation on my data using this code. I have the following ...
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21 views

Problems with curve fitting

I have a longitudinal dataset to which I am trying to fit the following model : $$ y_{i,j} = \frac{1}{1+a_{i} \exp(-r_{i}t_{i,j})} + \varepsilon_{i,j} \tag{1}$$ The setting : $i$ ($1 \leq i \leq ...
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7 views

Extract Rules from Matlab Classification Tree

I am using Matlab's ClassificationTree.fit to generate a classification tree for my data. Let's say I type: ...
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1answer
41 views

Determining order of AR model

Suppose that we have the following model $$ y[t] = A_1\sin(\omega_1 t+\phi_1)+A_2\sin(\omega_2 t + \phi_2)+ \cdots + A_p \sin(\omega_pt + \phi_p) + z(t) . $$ Let us call this signal as B. Then in ...
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29 views

Finding best parameters of SVM in matlab

I’m designing a system (using Matlab) that I can optimize parameters of a support vector machine (SVM) with genetic algorithm, harmony search and another optimization algorithms to find the best ...
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42 views

Conceptual issues in training neural network and learning curve

I have a 4 Input and 3 Output Neural network trained by particle swarm optimization (PSO) with Mean square error (MSE) as the fitness function using the IRIS Database provided by MATLAB. The fitness ...
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1answer
23 views

Should I specify Prior or Cost matrix with Tree Bagger in Matlab

I'm trying to create Random Forests in Matlab and there are more observations in some classes than there are in others. Do I need to specify this as a cost matrix or as a prior probability or will ...
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0answers
12 views

matlab error with LDA classification [migrated]

I want classify my data with LDA classifier. My test data size is: 1 12 240 64 And my train data size is: ...
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0answers
11 views

Can I use the Stationary wavlet transforming directly with GARCH models

I am trying to estimate and forecast the garch models directly with wavelet transforming but I am having an estimation error in the estimation step "constraints: 'Boundary Constraints Active; Errors ...
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41 views

HOG Feature Implementation with SVM in MATLAB

I would like to do classification based on HOG Features using SVM. I understand that HOG features is the combination of all the histograms in every cell (i.e. it becomes one aggregate histogram). ...
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1answer
38 views

Identify features corresponding to high singular/principal component values

In MATLAB, while SVD gives a diagonal matrix S of decreasing singular values, PCA gives a column vector LATENT of decreasing principal component values. How can S be used to obtain a subset of ...
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1answer
33 views

Linearly dependent features

I have a matrix A of 1000 observations (rows) and 100 features (cols). I would like to find: Linearly dependent features so that I can remove them and simplify the problem. rank(A) gives me 88, ...
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3 views

Write a matrix in a specific format to a text file from matlab [migrated]

I have this sparse matrix of size lets say NxM. I want to write the data into a file such that each line represents each row. Starts with the number of non zero entries in that row. Followed by the ...
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12 views

Test which method is better if data is gathered on overlapping time windows (not independent)

I have two methods which are being used to estimate a specific signal. I have a ground truth measurement of this signal and these two methods are using noisy data to estimate this signal. This signal ...
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2answers
83 views

How to calculate disparity of two images in matlab?

I have two images and I am trying to calculate the disparity between them using sum of squared distances and reconstruct disparity in 3D space. Do I need to rectify the image before calculating ...
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1answer
50 views

Are binomial and McNemar's tests right for my data?

I have performed an experiment, where I have real and synthesised movie data. My participants were shown either a real movie, or a synthesised movie (of talking heads), in a random order, and had to ...
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39 views

Ridge regression in Matlab produces different results than direct calculation [duplicate]

I am trying to run Ridge regression in Matlab (ridge): $L$ is some matrix, $x$ is some random vector and $y=Lx+\alpha n$ is another vector. I expect ...
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20 views

Difficulties in applying activation function in neural network

This is beginner level question. I have several training inputs in binary and for the neural network I am using a sigmoid thresholding function ...
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1answer
54 views

Is my understanding of this “confidence interval” solution correct?

I was faced with a problem of automatically detecting regions of continuity in a vector. I have a lot of these vectors, hundreds. One example of such vector is here. Basically looking at the vector, ...
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1answer
45 views

Simulating Diffusion/Wiener Process with Random Walk [closed]

I hope this is the right section for this kind of questions. I am trying to simulate, with MATLAB, a diffusion model starting from a Random Walk. I am using a Random Walk with information increment ...
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1answer
60 views

Comparing two curves with different x-axis points - appropriate test?

I have two curves and I want to be able to calculate the probability of these curves coming from different distributions or another appropriate statistic. Each curve is fitted through the mean of ...
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1answer
62 views

P-value NaN using chi2gof to validate lognormal distribution in dataset

I am trying to model a dataset of mine with a lognormal distribution using Matlab. I estimated the parameters via 'lognfit' and my generated datapoints with the fitted distribution look quite good ...
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1answer
48 views

Issue in training Hopfield network and convergence problem

I am learning how to use Hopfield Neural network as a context addressable memory. The objective is to obtain a fixed point of the network which indicates an equilibrium state. This state vector ...
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0answers
44 views

Matlab - draw biplot on nonclassical MDS interpration?

How can I draw similar biplot like you can on PCA, so I could compare these two vizualization techniques / methods? I got dissimilarities and distances of my data in simple plot, but I would like it ...
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1answer
33 views

Bivariate random variable with R [closed]

I am trying to transform this Matlab code into R. My goal is to generate a bivariate random variable with a pre-specified correlation. The code uses the idea of t-copula. I can't figure out how to ...
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0answers
26 views

Comparing isomap residual variance to pca variance

I am using R princomp function (from stats package) to run a PCA on a data set and I want to compare its output to that of the nonlinear dimensionality reduction method ISOMAP, which I am using under ...
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0answers
35 views

How to form Clusters from a Similarity Matrix in Matlab

I have a matrix stored in the matlab workspace that has similarity measures between documents stored using one of the similarity measure algorithm. Now, I want to identify the elements which have ...
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1answer
30 views

Normalized Variation of Information (NVI) visualization of distances to several references

I am using NVI (Normalized Variation of Information) to measure the quality of clustering obtained ( a family of them) compared to the Ground Truth and also to the result obtained with another method. ...
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0answers
10 views

Dictionary matrix for online sparse coding doesn't learn [migrated]

Following Online Dictionary Learning for Sparse Coding and using an inference function I've found on the Stanford's website, I'm trying to online learn a Dictionary matrix. Tested both on resized ...
2
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1answer
36 views

How to get a reciprocal plot from x and p(x)?

Let's say that I have a picture like the one in figure. This look like an histogram, but actually is not, in the sense that I did not produce the figure starting from a dataset of values. In fact, I ...