Data analytics, statistics, and more
The U.S. Drought Monitor is updated each Thursday to show the location and intensity of drought across the country, which uses a five-category system, from Abnormally Dry (D0) conditions to Exceptional Drought (D4). Using these data and the R statistical programming language, we can visualize drought severity across the United States for various time periods as static maps or even as an animated map
In this post, we explore three dimensionality reduction techniques specifically used for data exploration and visualization: principal component analysis (PCA), t-distributed stochastic neighbor embedding (t-SNE), and uniform manifold approximation and projection (UMAP).
In this post, we will use ordinal logistic regression to provide general contrasts on the log odds ratio scale as an alternative to nonparametric ANOVA. Proportional odds ordinal logistic regression is a generalization of the Wilcoxon and Kruskal-Wallis tests that extends to multiple covariates and interactions.
In this post, we will evaluate whether sample depth and/or site location affect arsenic concentrations measured in soil. To address non-normality and heteroscedasticity, two-way ANOVA will be performed using the rank-transformation of the data values.
This post summarizes influent flow data containing no measurement date for 10 wastewater treatment facilities.