intuition - What is perplexity? - Cross Validated
So perplexity represents the number of sides of a fair die that when rolled, produces a sequence with the same entropy as your given probability distribution. Number of States OK, so now that we have an intuitive definition of perplexity, let's take a quick look at how it is affected by the number of states in a model.
information theory - Calculating Perplexity - Cross Validated
In the Coursera NLP course , Dan Jurafsky calculates the following perplexity: Operator(1 in 4) Sales(1 in 4) Technical Support(1 in 4) 30,000 names(1 in 120,000 each) He says the Perplexity is 53...
autoencoders - Codebook Perplexity in VQ-VAE - Cross Validated
Jan 5, 2023 · When calculating perplexity, we are effectively calculating the codebook utilization. In the example above, if you change the low and high to a narrow range, then out of the 1024 codebook entries that we could have picked/predicted …
clustering - Why does larger perplexity tend to produce clearer ...
Mar 28, 2019 · The larger the perplexity, the more non-local information will be retained in the dimensionality reduction result. Yes, I believe that this is a correct intuition. The way I think about perplexity parameter in t-SNE is that it sets the effective number …
machine learning - Why does lower perplexity indicate better ...
The perplexity, used by convention in language modeling, is monotonically decreasing in the likelihood of the test data, and is algebraicly equivalent to the inverse of the geometric mean per-word likelihood. A lower perplexity score indicates better generalization performance. I.e, a lower perplexity indicates that the data are more likely.
Intuition behind perplexity parameter in t-SNE
Nov 28, 2018 · The perplexity can be interpreted as a smooth measure of the effective number of neighbors. The performance of SNE is fairly robust to changes in the perplexity, and typical values are between 5 and 50. What this effective number of neighbors would mean? Should I understand perplexity value as expected number of nearest neighbors to the point ...
How to find the perplexity of a corpus - Cross Validated
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Perplexity formula in the t-SNE paper vs. in the implementation
Mar 11, 2019 · The perplexity formula in the official paper of t-SNE IS NOT the same as in its implementation. In the implementation (MATLAB): % Function that computes the Gaussian kernel values given a vector of % squared Euclidean distances, and …
Inferring the number of topics for gensim's LDA - perplexity, CM, …
Jan 12, 2018 · Having negative perplexity apparently is due to infinitesimal probabilities being converted to the log scale automatically by Gensim, but even though a lower perplexity is desired, the lower bound value denotes deterioration (according to this), so the lower bound value of perplexity is deteriorating with a larger number of topics in my figures ...
How to determine parameters for t-SNE for reducing dimensions?
At a high level, perplexity is the parameter that matters. It's a good idea to try perplexity of 5, 30, and 50, and look at the results. But seriously, read How to Use t-SNE Effectively. It will make your use of TSNE more effective. For packages, use Rtsne in R, or sklearn.manifold.TSNE in python