Power Analysis for AB Testing (pwrAB)
Power analysis for AB testing. The calculations are based on the Welch’s unequal variances t-test, which is generally preferred over the Student’s t-test when sample sizes and variances of the two groups are unequal, which is frequently the case in AB testing. In such situations, the Student’s t-test will give biased results due to using the pooled standard deviation, unlike the Welch’s t-test.

The Grammar of Tables (tangram)
Provides an extensible formula system to quickly and easily create production quality tables. The steps of the process are formula parser, statistical content generation from data, to rendering. Each step of the process is separate and user definable thus creating a set of building blocks for highly extensible table generation. A user is not limited by any of the choices of the package creator other than the formula grammar. For example, one could chose to add a different S3 rendering function and output a format not provided in the default package. Or possibly one would rather have Gini coefficients for their statistical content. Routines to achieve New England Journal of Medicine style, Lancet style and Hmisc::summaryM() statistics are provided. The package contains rendering for HTML5, Rmarkdown and an indexing format for use in tracing and tracking are provided.

Helper Functions for Orthogonal Polynomials (polypoly)
Tools for reshaping, plotting, and manipulating matrices of orthogonal polynomials.

Calculating Marginal Effects and Levels with Errors (modmarg)
Calculate predicted levels and marginal effects from ‘glm’ objects, using the delta method to calculate standard errors. This is an R-based version of the ‘margins’ command from Stata.

Freshing Up your ‘ggplot2’ Plots (lemon)
Functions for working with legends and axis lines of ‘ggplot2’, facets that repeat axis lines on all panels, and some ‘knitr’ extensions.

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