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Questions tagged [keras]

Open source high-level neural network library for Python and R. Is capable of using TensorFlow or Theano as backend.

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Understanding epoch, batch size, accuracy ,performance gain in lstm forecasting model

I am new to machine learning and lstm. I am referring this link LSTM for multistep forecasting for Encoder-Decoder LSTM Model With Multivariate Input section. Here ...
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6 views

Finding correlations between multiple labels in neural networks

I am just posting with reference to another thread I read and would appreciate if anybody could offer some help. I am training a multi-label, multi class classifier in keras where my data has multiple ...
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need auc scoring with gridsearch in keras

I have unbalance dataset , i need to implement auc scoring in keras with gridsearch cv to find the best score. But in keras classifier auc and other metrics cannot be used directly , can anyone help ...
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15 views

Matrix formation and calculation for Collaborative filtering in Neural Network

Intution I am trying to implement Collaborative Filtering (User Based and Item Based) in Python Keras with neural networks. For user based CF with neural network, my input is rating matrix with ...
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6 views

Why do cross_val_score() and fit() return the last value, and not the best?

When you fit() a model, in let's say Keras, over a large number of epochs, chances are overfitting will occur. When supplied with a validation-set, you can easily find the point where the validation ...
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1answer
18 views

How can I store information in a custom regularizer? [on hold]

I'm trying to create a custom keras regularizer that uses the distance of the layer's weights from it's original weights, but what I used doesn't seem to work. I get a zero difference at all times. ...
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1answer
10 views

How Do I get 0 and 1 For multiclass multilabel problem in Keras prediction?

Let's say I have 3 classes, and each sample can belong to any of those classes. [ [1 0 0] [0 1 0] [0 0 1] [1 1 0] [1 0 1] [0 1 1] [1 1 1] ] I set my output ...
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1answer
30 views

Poor performance of LSTM classifier, almost always predicts one single class [closed]

I'm currently doing a multiclass problem, with 38 input variables and a 4 one-hot encoded vector as output. I've gathered a total of 8 time series with a grand total of 23977 rows. While my model ...
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13 views

Different metrics for GridSearch and Keras: which one is actually returned

During GridSearchCV/RandomizedSearchCV we have different options to use for scoring, 'accuracy' being the most popular. However, in the case of unbalanced classes, such metrics as "f1_macro" are more ...
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10 views

Autoencoder keeping constant vector as predict in keras [duplicate]

I'm new in keras and deep learning field. In fact, I want to make a dense vector for each document in my data so that i built a simple autoencoder using keras library. The input data are normalized ...
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10 views

How to make a sequence element-wise clustering with a RNN (preferable in Keras)

Non-Keras contributions are also welcome since the question is very concrete already. Imagine I have a sequence $S_i = s_0, s_1, ..., s_n$, where $s_k$ is the k-th element that represents an element ...
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Autoencoder - reconstructed image not matching the input image

I have trained a convolutional autoencoder on cifar10 dataset. The reconstruction loss on the test data is quite less (around 0.0225). However, the reconstructed training images do not look like ...
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1answer
19 views

Binary Classification of Numeric Sequences with Keras and LSTMs [duplicate]

I'm attempting to use a sequence of numbers (of fixed length) in order to predict a binary output (either 1 or 0) using Keras and a recurrent neural network. Each training example/sequence has 10 ...
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9 views

Handle loss while converting high dimensional image to specific size in VGG 16

I am training a VGG16 net using transfer learning. I have removed the fully connected layers and used fine tuning to classify objects into few categories but I have faced below problems: 1.I have ...
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21 views

Are there extant deep learning analogs to random coefficient (aka mixed) models?

Random coef models, applied to longitudinal data, capture response heterogeneity by cross-sectional unit. I've got a longitudinal prediction problem, in which I know that some "features" (or ...
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7 views

does feature normalization with Keras solves the color balance and illumination imbalance problem?

Keras ImageDataGenerator allows feature normalization as below: ImageDataGenerator(featurewise_center= True,featurewise_std_normalization=True) I am working with ...
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1answer
15 views

How could I go about implementing k-fold cross validation giving my circumstance?

The way I understand k-fold cross validation is that a given dataset or a training subset of the dataset is divided into k equal sets called folds. Then the training should be performed iteratively ...
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1answer
29 views

Help me interpret my VGG16 fine-tuning results

I have a binary classification problem where I'm trying to classify whether a given cell is cancerous or not. For this I decided to play around with VGG16 pre-trained model and simply remove the last ...
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27 views

train_accuracy and train_loss are not consistent in binary classification [duplicate]

I am training a binary classification algorithm in Keras, the loss is cross-entropy ...
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26 views
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18 views

Incorporating multiple categories to understand relationships between them in a sequential model

I have successfully built a a sequential model to stratify different organs of some genomic data that I have, and this works really well and with a high accuracy too. However, this is also time series ...
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1answer
66 views

LSTM - Multiple Time Series, degrading accuracy

I'm trying to make a LSTM model for detecting failures on a physical system, by supplying 27 features of sensor data. I've inputted three disjunct timeseries, each beginning with "normal" operational ...
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33 views

Accuracy of Keras Model is Very Low for Identifying Differently Colored Objects

I am using transfer learning approach to train my keras model to identify objects which have same structure but the colors are different i.e objects are to be identified by their respective color. ...
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1answer
58 views

why the accuracy of my CNN decreasing after some epochs?

at high accuracy, after some epochs the accuracy as well as validation accuracy is decreasing and got stuck after few more epochs. i dont understand why this happened. does more epochs at some point ...
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11 views

Why does the DCGAN output degrade with an increase in the kernel size?

Thank you for the explanation on the kernel size. I have been experimenting with the sample Generative Adversarial Network (GAN) code from the book on Deep learning with Python by François Chollet, ...
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12 views

faulty autoencoder [duplicate]

I am developing an autoencoder for CIFA10 dataset, without adding noise at the input (which is 2nd goal). The Convnet based autoencoder is not converging: Any suggestions ...
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23 views

Neuronal Network to approximate function from training samples [duplicate]

I'm trying to implement a neuronal network that approximates a certain function, although the term "function" here is mathematically probably imprecise and wrong. Anyway, here's the idea. I have a ...
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1answer
30 views

choosing metric for R keras for imbalanced binary class

i am using Keras on a text classification task in RStudio. I have a very imbalanced binary classification problem where the positive class is only present in about 2% of cases. If i use down-...
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25 views

High loss (low accuracy) on validation set but not on external test set

I'm training a neural network using 70% of my data as training set, 20% as external test set and 10% for validation using Keras. When I evaluate the trained model the performance on the validation set ...
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40 views

Multiclass Segmentation Using U-Net: My training loss is not decreasing after certain epoch (accuracy not increasing) [duplicate]

So the problem is to perform a multiclass segmentation (255 classes of crops), and I am using a U-Net model for that. The input images are grayscale and the images of dimensions (128,128,1) are ...
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1answer
28 views

how to build multiple independent binary logistic regression classifiers?

I have to build a logistic regression classifier to predict $\mathbf{y}$ given $\mathbf{x}$ where $\mathbf{x} \in \Re^{n}$ is an image and $\mathbf{y} \in \Re^{m}$ is a binary attribute vector (of $m$ ...
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0answers
23 views

How to plot the gradient descent of a RNN model built using keras? [closed]

I'm exploring how an LSTM solves the problem of vanishing gradients. I have created a simple LSTM model on keras. I know that model.fit() returns a history object that stores model loss and accuracy ...
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27 views

Machine Learning: Model doesn´t recognize letters but has 80% accuracy

I have build a model to classify numbers and characters on Images. I trained it on the Chars74K dataset and in training it has 80% validation accuracy. I just use the number and uppercase characters ...
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1answer
42 views

Creating a neural network that can make a decision with optional arguments

I'm a final year computer science student and for my final year project I have to design a neural network to play a little known board game called 'The Downfall of Pompeii'. I have to use ...
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14 views

NER with GRUs neural network with imbalance dataset

this is my first time asking question on CrossValidated, so if there is any mistake on my part, i apologize. I will try not to make those mistakes again. I'm trying to do a NER task. The problem is ...
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1answer
74 views

how does Keras ImageDataGenerator standardize data?

If I understand correctly the ImageDataGenerator class is a generator and returns batches of images when called, but what I don't seem to understand is: featurewise_center ...
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11 views

Dropdown in Validation Loss in the first epochs

I've built a classical backpropagation ANN using Keras for a regression problem, which has two hidden layers with a low amount of neurons (max. 8 per layer). The amount of samples for training and ...
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1answer
35 views

Feed Forward Neural Network Time Series Regression

I'm trying to use the Tensorflow regression tutorial (with Keras) to do some regression on a time series with a couple of inputs. I will provide code if asked so. My inputs are: [Day, Hour, Minute, ...
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60 views

Image classification with large images

I am new to image classification and hope to set up a model which will classify large images (I am using R keras). Each image will represent a 10m by 10m square with pixels representing 1 cm. I need ...
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58 views

Weighted binary crossentropy in U-Net has no effect on accuracy (dice coefficient)

I am currently working on implementing a weighted binary crossentropy loss function as described in the U-Net paper ...
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1answer
19 views

How to predict similarity of unseen data to the training set?

I have a time series of human pose data which are recorded from real humans. I want to train the model with unsupervised learning on the training data. Let's call this the "real" training data. The ...
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26 views

my CNN predict all 0 or all 1 in multi label classification problem

I am trying to build a CNN for classifying multiple objects in images. I'm on keras and I use the COCO dataset. my net takes in input a 256x256 image and outputs the vector of the predictions of each ...
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66 views

Why would one use gradient boosting over neural networks?

I'm referring to a specific Kaggle set: https://www.kaggle.com/c/petfinder-adoption-prediction There are a lot of columns, and I'm (for now) ignoring the images / videos. I'm training a standard ...
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1answer
57 views

Parameters Grid Search for Keras LSTM on Time Series

How do you do grid search for Keras LSTM on time series? I have seen various possible solutions, some recommend to do it manually with for loops, some say to use scikit-learn GridSearchCV. Feedback ...
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79 views

Why not use (nested) cross-validation to update weights when building final model?

I have been trying to find an answer to this question for some time. I understand that cross-validation is primarily used for model selection, i.e. to tune parameters/hyperparameters, but I don’t ...
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1answer
38 views

High AUC and Accuracy but weird output in confusion matrix

I am working on image classification problem to determine gender given a face. The dataset is located here gender face dataset on kaggle (link to my notebook). The class distribution is as follows. <...
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1answer
90 views

Higher value of strides in conv1d

I am using Conv1d for time-series data and I have create a model as follows, ...
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0answers
57 views

Fitting a neural network with more parameters than observations

I'm training a neural network for regression using keras with about 13k training observations, each with 40 features. It's a Sequential model with Dense layers. I generate random architectures for ...
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97 views

Time-series classification of Kinect data using Keras

For my PhD project I recorded using Kinect and Myo 11 people performing Cardiopulmonary Resuscitation (CPR), repeatedly doing chest compressions to a manikin (one person per time). I collected in ...
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16 views

GridSearchCV with one-hot y: prediction yields 1-dim array

I run a classification by means of a neural network, thus my y-values are converted to a one-hot matrix: ...