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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1answer
2k views

Avoid reloading DataFrame between different python kernels

Is there a way of keeping a variable (large table / data frame) in memory and share it across multiple ipython notebooks? I'd be looking for something, which is conceptually similar to MATLAB's ...
7
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1answer
2k views

How to draw a simple LSTM network

I'm new to deep learning, I am learning LSTM for my PhD work. This is a simple LSTM network for sequence classification. This code is from MATLAB tutorial: ...
5
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2answers
901 views

Data Visualization with multiple dimension, and linear separability

I have a dataset of two classes with several features, how can I visualise such data using Matlab to decide if it is linear separable or not?
5
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1answer
3k views

Using the cosine activation function seems to perform very badly

I have created a neural network to classify the MNIST handwritten numbers dataset. It is using softmax as the activation function for the output layer and various other functions for the hidden layer. ...
5
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1answer
191 views

how can I generate a Bernoulli block mixture model in matlab?

I am trying to write the code of a Bernoulli block mixture model in matlab, but am facing an error every time I run the function. In particular, I'm having a problem with how to relate the ...
4
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1answer
419 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 ...
4
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2answers
521 views

How to make sense of confusion matrix

Consider a binary classification problem with 0 labels denoting normal and 1 abnormal or rare. The number of instances with <...
4
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3answers
3k views

Same SVM configuration, same input data gives different output using Matlab and scikit-learn implementation of SVM, in a classification problem

I have a classification problem with 60 data points in a 2-dimensional feature space. The data originally is divided into 2 classes. Earlier I was using Statistics Toolbox of Matlab so it was giving ...
4
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1answer
355 views

Performance and architecture of neural network for increased dimensions

I posted this question on Cross Validated before I realized that this existed. I think it is better suited here and got no answers over there so I have deleted other post. I have reproduced the ...
4
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1answer
1k views

Is there a problem of over fitting in my dataset?

I have applied the sequential forward selection to my dataset having 214 samples and 515 features (2 class problem). The feature selection algorithm has selected 8 features. Now I have applied the svm ...
4
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1answer
594 views

Issue with backpropagation using a 2 layer network and softmax

I have a simple neural network with one hidden layer and softmax as the activation function for the output layer. The hidden layer uses various activation functions since I am testing and implementing ...
4
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1answer
285 views

Minimize correlation between input and output of black box system

I am not sure if "minimize correlation" is the right title for this issue but I could not find a better sentence to describe what I would like to achieve. Let's say that I have a black box with ...
4
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1answer
624 views

Implementing PatterNet in Python as it is in MATLAB

NOTE: This question was first posted in Cross Validated Stack Exchange but I was instructed to move it off that website as it was not a good fit. I am new in implementation of machine learning, neural ...
4
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2answers
170 views

How to find a changing relation between continuous variables?

I have a dataset with 8 continuous variables describing the behavior of a machine: - input a,b,c for both left and right: a_left, ...
4
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2answers
358 views

MATLAB Perceptron

I cant seem to figure out why I have a high percentage error. I'm trying to get a perceptron between X1 and X2 which are Gaussian distributed data sets with distinct means and identical co-variances. ...
3
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2answers
574 views

Setting best SVM hyper parameters

I have a non linear data set, and I am using SVM (RBF kernel) to build a classification model, but not sure how to set the best hyperparameters of the SVM, C and gamma in Matlab ...
3
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2answers
1k views

Why training and validation similar loss curves lead to poor performance

I am training a binary classification neural network model using matlab the graph that I got using 20 neurons in hidden layer is given below. the confusion matrix and graph between cross entropy vs ...
3
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1answer
197 views

Is splitting the data set into train and validation applicable in unsupervised learning?

I am having a tough time implementing all the steps of setting up support vector machine (SVM) for unsupervised learning. My data set is labelled but for educational purposes I am learning ...
3
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3answers
2k views

Which Format is Faster, Matlab (.mat) or NumPy (.npy)?

I am working on a deep learning problem to detect cancer in images of size 250 x 250. I have hardware limitations and I have been running out of memory. I decided to convert my images to Matlab ...
3
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1answer
723 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 ...
3
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1answer
238 views

Does CART algorithm takes into account in the order of the set of attributes?

when using matlab command 'fitctree' for classification purpose, and I change the order of the attributes I do not find the same Tree and thus the same classificaiton error? why? CART algorithm does ...
3
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1answer
373 views

How many features should I take out of 515 features?

In continuation to this question, I have a conceptual question. If I am not using the 'nfeatures' then I am getting 7 features from a feature set of 515 features. If I use the 'nnfeatures' tag (this ...
2
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2answers
762 views

Is it possible to connect three neural networks in Matlab?

If I have 3 separate feedforward neural networks in Matlab, is it possible to connect them so that, given input data and target data the 3 work in parallel to produce output? If so, how do I do this?
2
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2answers
439 views

Convolution Neural Networks on microcontrollers

I am wondering if an already trained convolutional neural network can be represented as a formula just like a perceptron can ($x_1w_1 + x_2w_2 + \ldots =$ PREDICTION). I know that the formula could be ...
2
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1answer
545 views

Can we implement random forest using fitctree in matlab?

There is a function call TreeBagger that can implement random forest. However, if we use this function, we have no control on each individual tree. Can we use the MATLAB function fitctree, which build ...
2
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1answer
5k views

K-Fold Cross validation confusion?

I am using K-Fold cross validation to test my trained model, but was amazed that for every K-fold the accuracy is different. For instance, if I use 5 K-fold, every fold has a different accuracy. So, ...
2
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2answers
378 views

Accuracy differs between MATLAB and scikit-learn for a decision tree

Is there any possibility to vary the accuracy of same data set in matlab and jupyter notebook by using python code ? For same data set, at first I applied it in matlab and get 96% accuracy for ...
2
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2answers
467 views

Terminology - cross-validation, testing and validation set for classification task

Confusion1) If k=10 then does this mean that 90% is for training and 10% for testing? So always we have k% for testing? ...
2
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2answers
2k views

How to rank a feature importance?

If I trained a network using Neural Network classifier, how can I know which feature was most important for predicting the target variable? I mean how to create a "feature ranking" among the features (...
2
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2answers
787 views

Outlier detection and removal using scatter-plots and histograms

Suppose, we use the following code to generate scatter plots, ...
2
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3answers
297 views

Obtain a model where each feature vector is past few samples and labels are future few samples?

So, I have this data set where each instance is made of past 20 samples of 2 variables. Labels are next five samples. So every instance looks like this: ...
2
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1answer
98 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 ...
2
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1answer
290 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 ...
2
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1answer
975 views

Training a convolutional neural network for image denoising in Matlab

I am currently trying to train CNNs to remove Poisson noise from images. The software I am using is Matlab 2018b, however the results I am getting are poor. I have followed the steps provided in the ...
2
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1answer
169 views

i need a characters /letters dataset for matlab

My final project is number plate recognition.i need a data set of A-Z characters and 0-9 letters. i donot find it on any website give me a data set or send me a link. i have to make a neural network ...
2
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1answer
170 views

ANN and prediction

I have a list of objects. Each objects contains longitude, latitude and a list of words. What I want to do is to predict the location based on the text contained in the object (similar texts should ...
2
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1answer
368 views

Vectorizing equation in MATLAB

I am working on collaborative filtering using matrix factorization in MATLAB. I am using Gradient Descent for parameter learning. The cost function to optimize is : $ J = {\left\| I \odot (R - U V') \...
2
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0answers
210 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 ...
2
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2answers
61 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: ...
2
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0answers
990 views

How to implement Moving window with LSTM for Time Series Prediction?

I am trying to implement a moving window in my dataset. The window size=14 (for instance).After implemntinf sliding window how to prepare inputs and outputs for netwok? ...
2
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0answers
416 views

Matlab: setting static iterations per epoch in a CNN

I'm building a convolutional neural network using Matlab's neural network toolbox. I have code designed to cross-train the network with different data sets, using the previous network's layers in ...
2
votes
1answer
183 views

Feature selection where adding features are deteriorating model

k I am training a kNN classifier with 144 features and graphed the accuracy vs number of features used and got this. What might be the reason for the drops in the accuracy at some points of the graph?...
2
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0answers
136 views

hmmtrain in Matlab converging to different values of trans and est over different runs

As the title indicates, over multiple runs of my program, I get different values of trans and est. Are these local minimum? If so how do I get the optimal one? NOTE - They all have the same starting ...
2
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1answer
117 views

Different accuracy for different rng values

While tuning the SVM classification model in Matlab, I came across the rng function in matlab in which seed (stabilizes the random shuffling of the data in the algorithm) is changed. When the function ...
2
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2answers
142 views

Different runs of feature selection algorithm giving different set of selected feature. How to choose the best set among them?

I am using the forward feature selection algorithm from MATLAB. The code is as follows: ...
2
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0answers
138 views

Parameters for CART tree

I'm using fitctree function from Matlab to fit a CART tree to my dataset (10'000 data points, 20 features). First, how can I exactly prune it and to what level should the tree be pruned? I think I ...
2
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1answer
125 views

Does the network learn based on previous training or does it restart? Matlab, neuralnetworks

In Matlab, if you build a simple network and train it: ...
2
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0answers
120 views

FUZZY ARTMAP for continuous data [closed]

I was going through an IEEE research paper which has used Fuzzy ARTMAP for predicting the price of electricity given some highly correlated data. As per my basic understanding about Fuzzy ARTMAP, it ...
1
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2answers
122 views

What type of optimization problem is this?

We have a deformable mirror controlled by 40 actuators that have input voltages from -1V to 1V. Prior to hitting the mirrors, a pulse of light enters a diffraction grating and then the light is spread ...
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, ...