Reinforcement Learning In reinforcement learning, an agent tries to come up with the best action given a state. For example, in the video game Pac-Man, the state space would be the 2D game world you are in, the surrounding items (pac-dots, enemies, walls, etc), and actions would be moving through that 2D space (going up/down/left/right). … Read more
TimeDistributedDense applies a same dense to every time step during GRU/LSTM Cell unrolling. So the error function will be between predicted label sequence and the actual label sequence. (Which is normally the requirement for sequence to sequence labeling problems). However, with return_sequences=False, Dense layer is applied only once at the last cell. This is normally … Read more
They are just different implementations of the same algorithm. The SVM module (SVC, NuSVC, etc) is a wrapper around the libsvm library and supports different kernels while LinearSVC is based on liblinear and only supports a linear kernel. So: SVC(kernel=”linear”) is in theory “equivalent” to: LinearSVC() Because the implementations are different in practice you will … Read more
1. K-medoid is more flexible First of all, you can use k-medoids with any similarity measure. K-means however, may fail to converge – it really must only be used with distances that are consistent with the mean. So e.g. Absolute Pearson Correlation must not be used with k-means, but it works well with k-medoids. 2. … Read more
OOF simply stands for “Out-of-fold” and refers to a step in the learning process when using k-fold validation in which the predictions from each set of folds are grouped together into one group of 1000 predictions. These predictions are now “out-of-the-folds” and thus error can be calculated on these to get a good measure of … Read more
If you use Keras, use CuDNNLSTM in place of LSTM or CuDNNGRU in place of GRU. In my case (2 Tesla M60), I am seeing 10x boost of performance. By the way I am using batch size 128 as suggested by @Alexey Golyshev.
It is a common practice to decrease the learning rate (lr) as the optimization/learning process progresses. However, it is not clear how exactly the learning rate should be decreased as a function of the iteration number. If you use DIGITS as an interface to Caffe, you will be able to visually see how the different … Read more
First of all, your question needs to define more clearly what you intend by Big Data. Indeed, Big Data is a buzzword that may refer to various size of problems. I tend to define Big Data as the category of problems where the Data size or the Computation time is big enough for “the hardware … Read more
SVD is not used to normalize the data, but to get rid of redundant data, that is, for dimensionality reduction. For example, if you have two variables, one is humidity index and another one is probability of rain, then their correlation is so high, that the second one does not contribute with any additional information … Read more
Suppose you want to write an algorithm that decides, based on two parameters, size and price, if an house will sell in the same year it was put on sale or not. So you have 2 inputs, size and price, and one output, will sell or will not sell. Now, when you receive your training … Read more