Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [matlab]

High-level language and interactive programming environment for numerical computing developed by MathWorks.

-1
votes
1answer
22 views

Confusion matrix in clustering [on hold]

Normally, the confusion matrix is associated with the classification since the actual class labels are known ahead for each data item. But, when you try to externally evaluate the clustering results, ...
1
vote
0answers
16 views

How can I determine, in what extent the fit to experimental data is good in Matlab?

I have experimental spectrum in which y-axis is intensity values, and x-axis is frequency values. Int - array of experimental intensities (y-axis). w - array of frequencies (x-axis). I know the view ...
3
votes
0answers
15 views

Quantifying a manifold folding unto itself

I have a dataset of ~7k scattered points in 3D which represents a manifold that may or may not "fold unto itself". Here's an example where this does happen (look at the top-right yellow triangles): ...
2
votes
0answers
32 views

How to train CNN for noise removal from images using Matlab [closed]

I am currently working on a project of mine where I want to use Convolutional neural networks for noise removal from images. I am talking about removing Poisson type of noise. The software that I am ...
0
votes
0answers
19 views

interprete and calculate Area Under the Curve of classifier in Matlab using perfcurve?

I hope that somebody could help me with the following question. I would like to calculate the Area Under the Curve (AUC) of a classifier (Linear Discrimiant Analyses). To do this, I am using the ...
0
votes
0answers
50 views

Compute log-likelihood from sum of squares?

I have fit a 2D Gaussian to a surface in Matlab and need to compute the log-likelihood of this fit. Can One use the sum of squares between the Gaussian model and the actual surface to compute the log-...
0
votes
0answers
16 views

FAVAR estimation Boivin et. al.(2009)

Boivin et. al. (2009) following the paradigm of BBE(2005) manages to decompose the fluctuations of each series into common and series specific components and study shocks into these components ? Do ...
0
votes
0answers
17 views

About the power spectrum and confidence upper limit

For now, I have a coupled system with 5 variables and use the Runge-Kutta method to integrate. ...
0
votes
0answers
18 views

Why LIBSVM provides incorrect accuracy when I am using it with '-b 1'?

I a beginner and trying to explore the libsvm library in MATLAB. I am giving exactly the same data for training and testing using,...
0
votes
0answers
32 views

Statistical test for binned proportion data in JMP / MATLAB

I have been trying to determine the proper statistical test for comparing binned proportional data between groups. My data set is individual subjects (4-5 per group) with 76-165 cells per individual. ...
0
votes
0answers
36 views

Naive Bayes where posterior almost always equals prior (in MATLAB)

I have trained a naive Bayes classifier in MATLAB using fitcnb (description link) and 11 variables, seven of which are numeric (normal) and four of which are categorical ("mvmn" distribution name). I ...
0
votes
0answers
12 views

Bayesian network (learn_struct_mwst)

I want to modeling a network with bayesian network. for finding the order i want to use learn_struct_mwst from nbt toolbox in matlab. can anybody help me to use this function? The code that i write ...
0
votes
0answers
23 views

possible to identify (2 or more) phases (left/right step) with SVM?

I am new to the field of machine learning and I am trying to create a tool which is able to identify if a left or a right step is performed on a wearable sensor which consists out of 3 sensors (...
1
vote
2answers
84 views

Distribution fitted well but kolmogorov -smirnov test not showing right results? Am I doing it right?

I want to do Kolmogorov -Smirnov test to see whether my data follows a particular distribution or not? When I fitted my data to lognormal distribution it fitted well. But When I am doing ks test, it ...
0
votes
0answers
12 views

Fluctuation in mean squared error

I am minimizing mean square error to find vector $f$, with some constraints, and my objective function is \begin{equation} E = f^{T}(R_{aa}-R_{ya}^{T}R_{yy}^{-1}R_{ya}^{})f^{} \end{equation} where $...
0
votes
0answers
20 views

Explain the results of the 2-sample Kolmogorov-Smirnov test for two random Gaussian sets of numbers

Suppose I have two sets of random numbers drawn from the Gaussian distribution, $\mathbf{r_1}$ and $\mathbf{r_2}$. I then do a 2-sample Kolmogorov-Smirnov test (KS test) between the two to determine ...
0
votes
0answers
73 views

Trying to understand the Kolmogorov-Smirnov test in MATLAB

I have two sets of data, $\mathbf{d_1}$ and $\mathbf{d_2}$ which I want to test to see if they are drawn from the same distribution using the two-sample KS test in MATLAB. My understanding of the KS ...
1
vote
0answers
30 views

How to understand the results of nonlinear mixed-effects regression model

I have some data, obtained from 4 different groups. Each repeat is some 4 parametric sigmoid. I need to fit the data to sigmoidal function and answer the question, whether sigmoids are different ...
0
votes
0answers
22 views

How to obtain the 1D radial correlation function from the 2D ACF

The two-point correlation function Z2 is defined as the probability that two points separated by a distance r will both lie in ...
0
votes
1answer
37 views

Algorithmic or structural limitations of space-filling Latin hypercube sampling

I'm new to Latin hypercube sampling, and am trying to understand if the somewhat odd sampling that results from the Matlab function lhsdesign is a limitation of the ...
0
votes
0answers
60 views

Logistic regression with negative weights in Matlab

I want to apply a logistic regression to a set of data where observations have been assigned weights depending on their "distance" from {0,1}. Most of the observations have weights within [0,1] range, ...
2
votes
1answer
49 views

Backpropagation in a logarithmic layer of a regression NN

A "logarithmic neuron" is defined as follows [1]: Which for inputs $\left\{ {{x_1},...,{x_n}} \right\}$ yields an output of $z=\prod\limits_{i = 1..n} {x_i^{{w_i}}}$ (in MATLAB, the activation ...
2
votes
0answers
71 views

Robust Regression in MATLAB's robustfit: what is the optimal weight function to tackle heteroskedasticity?

I'm currently performing a linear regression analysis and encountered a fair amount of heteroskedasticity. Increases in predicted values go along with decreases in residual variance. Otherwise, the ...
0
votes
0answers
16 views

How to calculate image similarity between 2 images using DTV?

I try to implement Differential total variation (DTV) as described in (Wu, Y. et al 2017) or (Li, Y. et al 2015). (Wu, Y. et al 2017) describe DTV as following My DTV Matlab function is ...
0
votes
1answer
50 views

Tukey-Kramer or Nemenyi following Friedman

I previously asked a question here after discovering an option by MATLAB to run Tukey-Kramer for multiple comparison multcompare following Friedman test and many ...
2
votes
0answers
48 views

Why Linear Discriminant analysis in MATLAB and R are producing different results

I am applying manova and lda to my data 12 samples (6 groups with 2 samples in each) and 6 measurements. I used lda form MAS5 package in R and different LDA functions in MATLAB. They all gave me ...
1
vote
0answers
12 views

Find data in an array above certain percentile for consective days

I have a time series for 10 years of observations. i want to find number of events when the values are above 90th and 80th percentile for consecutive three days.Further i need to find the length of ...
1
vote
1answer
132 views

How to perform kFold cross validation in Libsvm's precomputed kernel in MATLAB?

I understand that Libsvm provides 'v 10' option for 10-fold cross-validation in...
1
vote
0answers
13 views

Relationship of confidence interval of parameter estimated and regression bounds

I am using Matlab and have fitted a line of the form y=ax+b using the curve fitting tool box. In the output I get the estimates for ...
2
votes
0answers
31 views

Why does centering the regressor at a nonzero value improve performance? [closed]

I'm trying to understand why centering myregressor at a nonzero value improves the performance. I always thought that the variance of the feature, and its correlation with the labels, would affect ...
-1
votes
1answer
25 views

Device grouping using k-means to create clusters with overlapping neiborhoods

I want to use k-means to group (cluster) my devices into overlapping regions. For example I randomly generate the locations of my node devices on an $XY$ plane such as $n_1$ at location $(x_1,y_1)$, $...
1
vote
0answers
13 views

Performing regression with 1-d response and a 2-d predictor?

I have a dataset I'm trying to figure out how to properly analyze. I'm exploring both how hours spent studying and timing of preparation correlate with test outcomes. The model is as such: response =...
0
votes
0answers
18 views

multivariate multiple regression, testing if a variable leads y's at the same time

I have a what I understand to be a multivariate multiple predictive regression. The y's are different variables and I am attempting to see if these are lead by w at the same time. I use the standard ...
0
votes
0answers
25 views

Decision tree probability score in MATLAB

How does 'predict' function in MATLAB compute probability scores for predictions for binary classification trees?
0
votes
0answers
18 views

Confidence intervals for estimated means in multimodal Gaussian Mixed model

I am trying to define animal behaviors by using a distribution of turn angles from 0-180 obtained from animal locomotion. My plan is to use the angle distribution to determine a range of angles to use ...
0
votes
0answers
10 views

Deconvolution of 2 vectors (1 know + 1 unknown)

I am currently trying to deconvolute 2 vectors (a & b) from 1 (c). Actually, I have access to the recorded data of (a) & (c) but not (b). All are signal vs time with signal totally random. I ...
0
votes
1answer
50 views

Clustering visited vertex in a graph

I would like to know can anyone introduce me an algorithm to cluster multiple sequence of visited vertices in a graph. For example assume your graph has 6 nodes. following might be 3 different ...
0
votes
1answer
90 views

Educational purpose :Calculation of sensitivity and specificity from confusion matrix for this example

Consider a case where the number of labelled data as 0 = 1400 and labelled as 1 =100. The data labelled as 0 denote normal operating conditions and data labelled as ...
1
vote
1answer
141 views

Matlab Classification Learner App vs. own code: Why is there a difference between Leave-One-Person-Out and 10-fold Crossvalidation?

I am trying to find a good model to explain my dataset. The problem is that I want to do leave-one-person-out cross validation which is not available in the Matlab Classification Learner App. So I ...
0
votes
0answers
27 views

autoencoder parameters effect matlab

i'm new in autoencoders and matlab i'm applying this tutorial https://www.mathworks.com/help/nnet/ug/construct-deep-network-using-autoencoders.html after extrating the features i'm trying to check ...
2
votes
1answer
46 views

How can we determine where the relationship is not linear anymore?

My data look like the following figure. I want to figure out at which point the relationship between y and x starts to become linear. Let’s call this point $x_0$. Let me divide my question into three ...
-2
votes
1answer
77 views

Why isn't Matlab's Classification Learner the End All? [closed]

After building some machine learning models in Python, R and Matlab, I found the latter's Classification Learner App to be immensely powerful. In the time it took me to build a single model in Python ...
1
vote
1answer
86 views

Regression: very basic questions [closed]

I am about to implement the regression. Since I am analyzing on my own, and have almost zero practical know-how of statistics, I doubt myself a lot (plus the results I have obtained so far look 'weird'...
1
vote
0answers
30 views

Finding an Analytical Relationship Between Variables

I have a spreadsheet read from a metheorological system with a simple model embedded. I solved the most variables by simple inspection and through related literature, but unfortunately, the literature ...
0
votes
0answers
62 views

Kernel regression: Bandwidth selection on subsample

I have two columns of data which I sort by size (ascending) of the second column. I now want to execute a kernel regression on the first column (Nadaraya-Watson estimator) and I am interested in only ...
7
votes
1answer
162 views

Confidence bounds for an ECDF

I'm attempting to create an ECDF (and a confidence bound) from data in Python. I can generate the ECDF fairly easily with numpy by sorting and using ...
0
votes
1answer
39 views

How can I test PCR model?

I'm new to modeling principle component regression. I used MATLAB documentation to see an example on how to do it using the built-in functions. I just want to know how to test the model to try other ...
0
votes
1answer
126 views

Automatic relevance determination Kernel for GPR in sklearn

I have checked the performance of my model with the different kernel and seems ARD kernels, where each estimator has different length scale performance better than normal kernels. ARD kernels are not ...
0
votes
0answers
23 views

ARMA / ARMAX with nonlinear cross terms

Assume I have a multi variable ARMAX model. I would like to evaluate the influence of including cross products of the inputs. I could just calculate the cross products and include them as inputs for ...
0
votes
0answers
94 views

Fully Convolutional network (FCN) desired output

I am trying to implement a simple FCN in matlab from scratch. I have implemented 1 input(single channel image) neuron, 3 hidden layers with 3 neurons and one output neuron at end of the network as the ...