Julian M. Del Fiore

Intuition To check whether we are dealing with a rotated sorted list or not, we could sort the list, test all possible combinations, and then if we find one that works, we know the list was sorted. However, there is a solution that does not require sorting the list. [Read More]

Cartesian and polar coordinates [Read More]

I sometimes need a function, and want it to be both weird and sexy. To define this function, I want to be unstructured, I don’t want to limit my imagination. I want to be able to define a set of ordered points, and then have a function that when plotted,... [Read More]

Softmax regression is a supervised machine learning algorithm used in classification tasks where a target variable $y$ may take $K$ values, and we are interested in labeling an observation composed of $N$ features/predictors. While workarounds such as OvR and OvO allow to use binary classifiers (e.g. logistic regression) in multinomial... [Read More]

Linear discriminant analysis (LDA) and quadratic discriminant analysis (QDA) are supervised machine learning algorithms used for multinomial classification tasks. Both LDA and QDA estimate $P(y \;\vert\;\mathbf{x})$ relying on Bayes theorem, i.e., first calculating $P(\mathbf{x} \;\vert\; y)$, and eventually $P(y)$ too. For each class $k \in \{1, \ldots, K\}$, LDA assumes... [Read More]