I was implementing some sample Neural networks and in most tutorials saw this statement.
Neural networks tend to work better on GPUs than on CPU.
The scikit-learn framework isn’t built for GPU optimization.
So does this statement (work better) refers solely regarding the train phase of a neural network or it includes the prediction part also. Would greatly appreciate some explanation on this.
That statement refers to the training phase. The only issue here is that you can explore the search space of feasible models in a more efficient way using a GPU so you will probably find better models in less time. However, this is only related to computational costs and not to model predictive performance.
Related
I followed all the steps mentioned in the article:
https://stackabuse.com/tensorflow-2-0-solving-classification-and-regression-problems/
Then I compared the results with Linear Regression and found that the error is less (68) than the tensorflow model (84).
from sklearn.linear_model import LinearRegression
logreg_clf = LinearRegression()
logreg_clf.fit(X_train, y_train)
pred = logreg_clf.predict(X_test)
print(np.sqrt(mean_squared_error(y_test, pred)))
Does this mean that if I have large dataset, I will get better results than linear regression?
What is the best situation - when I should be using tensorflow?
Answering your first question, Neural Networks are notoriously known for overfitting on smaller datasets, and here you are comparing the performance of a simple linear regression model with a neural network with two hidden layers on the testing data set, so it's not very surprising to see that the MLP model falling behind (assuming that you are working with relatively a smaller dataset) the linear regression model. Larger datasets will definitely help neural networks in learning more accurate parameters and generalize the phenomena well.
Now coming to your second question, Tensorflow is basically a library for building deep learning models, so whenever you are working on a deep learning problem like image recognition, Natural Language Processing, etc. you need massive computational power and will be processing a ton of data to train your models, and this is where TensorFlow becomes handy, it offers you GPU support which will significantly boost your training process which otherwise becomes practically impossible. Moreover, if you are building a product that has to be deployed in a production environment for it to be consumed, you can make use of TensorFlow Serving which helps you to take your models much closer to the customers.
Is there any equivalent/alternate library to fastai in tensorfow for easier training and debugging deep learning models including analysis on results of trained model in Tensorflow.
Fastai is built on top of pytorch looking for similar one in tensorflow.
The obvious choice would be to use tf.keras.
It is bundled with tensorflow and is becoming its official "high-level" API -- to the point where in TF 2 you would probably need to go out of your way not using it at all.
It is clearly the source of inspiration for fastai to easy the use of pytorch as Keras does for tensorflow, as mentionned by the authors time and again:
Unfortunately, Pytorch was a long way from being a good option for part one of the course, which is designed to be accessible to people with no machine learning background. It did not have anything like the clear simple API of Keras for training models. Every project required dozens of lines of code just to implement the basics of training a neural network. Unlike Keras, where the defaults are thoughtfully chosen to be as useful as possible, Pytorch required everything to be specified in detail. However, we also realised that Keras could be even better. We noticed that we kept on making the same mistakes in Keras, such as failing to shuffle our data when we needed to, or vice versa. Also, many recent best practices were not being incorporated into Keras, particularly in the rapidly developing field of natural language processing. We wondered if we could build something that could be even better than Keras for rapidly training world-class deep learning models.
I am studying about Google's brandnew MobileNetV2 architecture.
During studying, I've read this string at Tensorflow model zoo Github
'For example Mobilenet V2 is faster on mobile devices than Mobilenet V1, but is slightly slower on desktop GPU.'
So, my question is,
How that could be possible? I really want to know why.
From https://arxiv.org/abs/1903.08469v1 :
"However, MobileNet V2 uses depthwise separable convolutions which are not directly supported in GPU firmware (the cuDNN library). Therefore, MobileNet V2 tends to be slower than ResNet18 in most experimental setups. Note that the same issue disqualifies usage of the DenseNet architecture [12], since it requires efficient convolution over a non-contiguous tensor, which is still not supported in cuDNN."
From their published paper at MobileNetV2: Inverted Residuals and Linear Bottlenecks,
under subtopic number 5: Implementation Notes, 5.1. Memory efficient inference;
The inverted residual bottleneck layers allow a particularly
memory efficient implementation which is very
important for mobile applications. (and more in paper)
According to TensorFlow team, it's optimized smaller in size can also be used as TF Lite. As far as we know TF Lite is indeed for mobile use. It's much slower on desktop GPU probably V2 has more conv layers compared to V1 which make sense if the training tooks more times to finish. For now, we didn't do the training and inferencing of data on mobile because of computational speed hunger which lead to power hunger as well.
Hope I answer the question.
I've implemented the Neural Network using Tensorflow. During the implementation and training, I've found several not-so-trivial bugs.
Example: during the training I had same Mini-Batch loss for different steps/epochs, but different accuracy.
Now the neural network seems to be ready and working properly. I haven't managed to train it well yet, but I am working on it.
Anyway, I would like to check somehow that I haven't done any computational errors there. I am thinking about generating some artificial data for "fake" classification problem with lets say 4 features. The classification should have a very clear human-understandable dependency between the classification output and 4 features. The idea is to try to train the NN on it and see how it performs.
What do you think?
Stanford's c231n has a couple of general tips for this, like gradient checking.
If you're just learning neural networks, why don't you try to run your implementation on some known data? Many courses provide error and loss curves form models with specified hyperparameters, so you can check whether your implementation's behavior differs significantly from correct implementation.
Is the TensorFlow designed only for implementing neural networks? Can it be used as a general machine learning library -- for implementing all sorts of supervised as well as unsupervised techniques (naive baysian, decision trees, k-means, SVM to name a few) ? Whatever TensorFlow literature I am coming across is generally talking about neural networks. Probably graph based architecture of TensorFlow makes it suitable candidate for neural nets. But can it be also used as a general Machine Learning framework?
Tensorflow does include additional machine learning algorithms such as:
K-means clustering
Random Forests
Support Vector Machines
Gaussian Mixture Model clustering
Linear/logistic regression
The above list is taken from here, so you can read this link for more details.