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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15 views
Results of quadratic SVM in Matlab are different from the results obtained in Python
I am trying to replicate a quadratic SVM classifier from Matlab to Python, however I am having different results regarding the accuracy. In Matlab the accuracy is 0.8955 meanwhile in Python the ...
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34 views
Looking for a machine learning algorithm that can classify line plots into two groups?
I have a dataset of many 2-D line plots that represent height versus position measured from an AFM.
I am interested in training a model by classifying these lines into two groups: presence of a defect ...
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0answers
11 views
Machine learning to find defects in material
if I have voltage against time for different points in a material from ultrasonic testing, is it possible to use machine learning to identifies the echoes? I am using MATLAB and I'm wondering if it is ...
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1answer
27 views
How to calculate the different metrics for multi class classification
My confusion matrix has the following structure:
(Predicted)
C= ( actual) [TN FP
FN TP]
How can I calculate the Mathews ...
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1answer
31 views
MNIST 2-layer NN failing to recognize certain digits
Recently I've been taking a look into some basic multilayer neural networks, and I decided to try tackling the MNIST database of handwritten digits using a 2 layer neural network with 100 neurons in ...
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0answers
21 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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1answer
34 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, ...
1
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1answer
35 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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54 views
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112 views
How to estimate tail distribution for computing Conditional Value at Risk in python?
How to estimate parameteres of generalized pareto distribution in python? š
I solve the task of computing Value at Risk and Conditional Value at Risk.
...
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2answers
77 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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1answer
19 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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0answers
20 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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0answers
18 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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0answers
14 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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0answers
19 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
71 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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0answers
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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0answers
6 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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78 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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0answers
17 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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1answer
47 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 ...
2
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1answer
234 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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0answers
163 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 ...
3
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1answer
535 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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1answer
469 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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1answer
43 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 ...
1
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1answer
35 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 ...
0
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1answer
45 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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0answers
20 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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0answers
30 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
198 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...
Iām only seeing this when I run the code:
It literally isnāt outputting anything.
This is what my chart looks ...
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1answer
54 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
51 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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0answers
74 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
331 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 doesnāt 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
63 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
57 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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0answers
19 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
...
2
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0answers
23 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
228 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
41 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
228 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
33 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
53 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 ...
4
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1answer
375 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 ...
2
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3answers
173 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
660 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 ...
