Questions tagged [matlab]

MATLAB is a high-level language and interactive programming environment for numerical computation and visualization developed by MathWorks. Don’t use both the [matlab] and [octave] tags, unless the question is explicitly about the similarities or differences between the two. When using this tag, please mention the MATLAB release you're working with (e.g. R2017a).

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12 views

How do I apply radon and iradon function in a 3D image

I am using matlab image processing , I have a 3DBodyphantom image of a CT scan which displays the axial,coronal and saggital slices, I am to apply to the image the radon function to get a sinogram and ...
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33 views

How to get used to matricial/vectorial operations?

I came to data science/machine learning from another background in computer science and i feel that i'm lacking of experience with matricial/vectorial operations. Python or Matlab, for instance, ...
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32 views

how to read emotion label of MSP-IMPROV dataset samples?

I need to read MSP-IMPROV dataset audio file's to conduct research. I read the help file that says 15th character of the file name, shows the emotion label of each utterance. For example: MSP-IMPROV-...
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34 views

Matlab - Exact Line Search

This is code for inexact line search: ...
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58 views

How to estimate tail distribution for computing Conditional Value at Risk in python?

How to estimate parameteres of generalized pareto distribution in python? 🙏 I solve the task of computing Value at Risk and Conditional Value at Risk. ...
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2answers
65 views

How to find the average over an area of center for a given radius

folks, I have an excel file which contains the lat and long values of the center of a Tropical Cyclone(TC). The excel file is as given below: Also, I have an NC(NetCDF) file which is of that of ...
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16 views

Optimization function returns the same optimal parameters for two labels

I've recently enrolled in the Coursera machine learning, and am working my way through making my own classifier for the Iris dataset problem using matlab. I'm training a classifier for each species (...
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15 views

looking for a correlation function for categorical + numerical datasets in matlab

I am looking for a function in Matlab that calculates the correlation coefficient of a data set that includes categorical + numerical data. I am quite surprised this isn't as straightforward as I ...
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14 views

Matlab Optimization. Meaning of warning: “The slope should be 2. It appears to be 1.”

I'm using the manopt package to solve some optimization problems in matlab. The problem is of the form. problem.cost = @(x) f(x) problem.egrad = @(x) g(x) After the problem definition, I check ...
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13 views

huge disbalance between Dc and Dm in gradient descent

i get a huge gap in my starting position between Dc and Dm and although they both go down in each itteration,still the gap is so huge that when one comes close to zero the other is still very large ...
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18 views

gradient descent regression in matrices form diverges

I am trying to build fit the best fit for my random distribution. I have done exactly by the formulas in the book shown bellow. I get divergence in the error function. Where did I go wrong? my Matlab ...
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1answer
68 views

gradient descent diverges extremely

I have manually created a random data set around some mean value and I have tried to use gradient descent linear regression to predict this simple mean value. I have done exactly like in the manual ...
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17 views

Optimization problem with different type of constraints

I'm new to optimization problems. I want to find optimum values for my objective function. You can imagine my function as E = f(t1, t2, t3). I want to minimize <...
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4 views

I want to use a neural network for a control block in MATLAB, but without Simulink

I have a physical model that produces an error value after running, which I want to minimize by a Neural Network. I can not find a MATLAB function however that lets me run the program and use the RMSE ...
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55 views

Policy Gradient with Baseline Reward Oscillation (MATLAB Reinforcement Learning Toolbox)

I'm trying to train a Policy Gradient Agent with Baseline for my RL research. I'm using the in-built RL toolbox from MATLAB (https://www.mathworks.com/help/reinforcement-learning/ug/pg-agents.html) ...
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1answer
16 views

Why normalize function has a different result on a matrix vs single value?

I have a matrix like: B=[ 1.5035; 1.5728; 1.6485; 1.5369; 1.5467; 1.572; 1.5374; 1.787; 1.5825; 1.6905]; Using normalize function like normalize(B,'range') ...
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16 views

Embedding git commit into the resulting data

Our pipeline works something like that: Collect bunch of raw data (10-100 GB) from microscope Process data using MATLAB scripts Change few parameters based on raw data, as well as add new features to ...
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19 views

Matlab - Financial Modeling, Linear Regression with Prior

Am trying to implement this equation from the book Doing Data Science Straight Talk from the frontline, In chapter 6, page 161, equation below: From what i can tell it is pretty much an enchanced ...
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1answer
40 views

kmean clustering

I am having a problem in Matlab. I would like to use kmeans clustering and then get the value and index of the centroid. For example, if there is an $5*5$ array, we do kmeans clustering where k=2 and ...
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1answer
175 views

Hyperparameter optimization performance comparison

I have used Bayesian optimization for hyperparameter tuning in a machine learning model. What is the best way to compare the performance of network with and without Bayesian optimization? I found some ...
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141 views

Using LSTM to forecast vehicle position - multivariate time series - Matlab

I am trying to train an LSTM model on Matlab to forecast the position of a vehicle when driving around a roundabout. My main concern right now is that my dataset consists of 4 features (X position, Y ...
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1answer
360 views

How to find the various matrix sizes in designing a CNN

I am trying to understand CNN especially the maths and working mechanism using Matlab as the coding language. I have few confusion regarding the concept and the associated programming and will be ...
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15 views

How to use ttest on kfold data test results?

I used K-fold and partition my dataset to 10 sets of train and test after that put the result for every folds on a table, now I have 10 sets of results. After it get average of every column(my ...
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385 views

Tensorflow simple neural network has very bad performance in regression (curve fitting) problem

I'm trying to implement a very simple one layered MLP for a toy regression problem with one variable (dimension = 1) and one target (dimension = 1). It's a simple curve fitting problem with zero noise....
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39 views

Is it possible to change test and train data size when using crossvalind function with Kfold param?

I was looking at MATLAB Help and want to work with "crossvalind" function. It would two parameters that you can use it. If you use "HoldOut" you can define partition size of test and train data set ...
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1answer
33 views

Is there a common strategy to measure if a difference-significance of two areas under two ROC curves

I conduct sound detection experiments with mice. I have a stimulus sound and a "noise" sound that shoukd be ignored. I want to measure how well the mouse ignors the noise (with respect to, say, ...
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1answer
30 views

Why GA convergence curves continue as two parallel lines?

I'm working on a optimization problem and using GA algorithm (in MATLAB, ga function). As you know MATLAB plots GA result with two curves, one for the best values and other to show the mean values ...
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1answer
42 views

What method is recommended after outliers removal?

I have a data of mice reaction times. In every session, there are some trials in which the mouse "decides of a break" and responds after a long time to these specific trials. I was thinking ...
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19 views

Octave or python for implementing Machine Learning [closed]

When is the need to learn octave or Mat Lab for Machine Learning? Are these required if you are proficient in python?
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28 views

Why do the training curve fall sharp suddenly?

I am training a CNN classifier on a binary balanced dataset. The dataset has 4500 numbers of tweet data along with the class of the tweet. During training, I am applying, GLOVE embedding of 300 ...
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1answer
172 views

Why is my Python Altair chart printing a blank line?

Wondering if anyone can help me understand why python altair chart is not printing... I’m only seeing this when I run the code: It literally isn’t outputting anything. This is what my chart looks ...
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1answer
51 views

Feature selection method explanation

In the context of feature relevance, I am trying to understand the meaning of the correlation method for feature selection. Can somebody please explain if the following results of the correlation ...
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1answer
50 views

Modelling in python and scoring in MATLAB?

I have model objects either pickled object or H2O POJO. Is it possible to call those objects and do the scoring in MATLAB?
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71 views

How to implement loss function for CNN-SVM implementation

I am using Matlab R2018b and am trying to infuse svm classifier within CNN. My plan is to use CNN only as a feature extractor and use SVM as the classifier. I know people have already implemented it a ...
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1answer
321 views

What should I master better for professional data science in economics and finance? [closed]

First, excuse me for the noob and long question which is probably doesn’t even belong to here, I know there are several question been answered like this out there, but I think this is going to be up-...
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1answer
53 views

How to store a trained Random Forest model in python or matlab as a matrix

Is it possible to store a random forest model in python (or matlab). Then use that trained model in a C program? I am trying to do this because I am making a myoelectric prosthetic, and you can only ...
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2answers
55 views

Finding roots of a non linear expression when multiplied with a linear expression

Here is a simple polynomial equation: b^2 + 2b + 1 = 0 I could easily solve this as: ...
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16 views

Error using imread function in matlab code

I was doing some sort of speech recognition pattern for recognition of sound but I stuck at imread error in matlab, any advice what to change in picture below you can find code and error. Code Error ...
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22 views

How to develop this type of neural network? [closed]

I was given this task to develop, this type of neural network but I never done speech recognition and that type of recognition in Matlab, so could anyone please help and give some help about this task....
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2answers
189 views

Shouldn't an autoencoder with #(neurons in hidden layer) = #(neurons in input layer) be “perfect”?

I'm exploring autoencoders for the first time. I'm using the Matlab neural networks toolbox. I have created a synthetic dataset consisting of points in 2D space plus some noise. My idea was to ...
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1answer
36 views

What's the correct form of use the real coded genetic algorithm?

I'm new to genetic algorithms, but I haven't found specific info about real-coded GA's. I want to do antenna array optimization by using the real values of antenna position, phase, and amplitude, but ...
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1answer
176 views

How to find which features have been selected by PCA algorithm?

I used PCA function in MATLAB to decrease features on my data set. By this code I can reduce features from 12 to 8(as an example). It works good but my question is that how can I found with feature ...
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1answer
32 views

Does PCA decrease the feature on my Data set or just decrease the dimension?

I'm new in AI and sorry if my question is simple. I have a data set and want to use PCA to decrease the feature but after some research on the internet I'm confused about decreasing dimensions and ...
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2answers
51 views

Linear regression incorrect prediction using Matlab

In the plot below the red crossed line is the actual curve and the crossed blue line is the predicted curve. I am using least squares for linear prediction. I have used 1:79 examples in training and ...
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1answer
355 views

Training a classifier when some of the features are unknown

I am training a classifier in Matlab with a dataset that I created. Unfortunately some of the features in the dataset were not recorded. I currently have the unknown features set as -99999. So, for ...
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3answers
160 views

Why are pandas/R/etc so common in a data scientist or analyst's workflow when one can resort to UDFs in an RDBMS?

It seems common for an analyst to have this workflow when using an RDBMS: use SQL to get a subset of data from the database, export it or use a connector, and then apply a data mining / model ...
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1answer
597 views

Advice on transitioning from Andrew Ng's Stanford Coursera Machine Learning (in MATLAB) into Python?

I'm currently finishing up Andrew Ng's Coursera course, taught in MATLAB/Octave, but I'm looking to code in Python. The course is an introduction into how some algorithms work from scratch. These ...
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1answer
205 views

Tuning C hyper parameter in Soft Margin SVM in Matlab

How to tune the C 'BoxConstraint' hyperparameter in soft margin SVM to get the best optimal value?
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2answers
67 views

Where can I find an algorithm for human activity classification using thigh and shank sensors?

I am working on a project where I initially need to classify the type of activity a subject is performing based on raw accelerometer and gyroscope data from the thigh and shank of both legs. The type ...
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307 views

SVM hard and soft margins in matlab,

I am comparing the performances of several SVM models in matlab using the fitcsvm function, and I want to double check that I am using the correct syntax for hard ...