Update Oct-23: Added a new parameter add to the function. Now multiple groups can be plotted in a single plot (see example in my comment) As a follow-up on my R implementation of Solomon’s watercolor plots, I made some improvements to the function. I fine-tuned the graphical parameters (the ... [Read more...]

Dear valued customer, it is a well-known scientific truth that research results which are accompanied by a fancy, colorful fMRI scan, are perceived as more believable and more persuasive than simple bar graphs or text results (McCabe & Castel, 2007; Weisberg, Keil, Goodstein, Rawson, & Gray, 2008). Readers even agree more with fictitious and ... [Read more...]

[Update 1: Sep 5, 2012: Explore the Magical Data Enhancer by IRES, using this visualization technique] [Update 2: Sep 6, 2012: See new improved plots, and new R code! Solomon Hsiang proposed an appealing method for visually displaying the uncertainty in regressions (see his blog [1][2], and also the discussions on the Statistical Modeling, Causal [...] [Read more...]

I currently program an automated report generation in R – participants fill out a questionnaire, and they receive a nicely formatted pdf with their personality profile. I use knitr, LaTex, and the sendmailR package. Some participants did not provide valid email addresses, which caused the sendmail function to crash. Therefore I ... [Read more...]

For the presentation of norm values, often stanines are used (standard nine). These values mark a person’s relativ position in comparison to the sample or to norm values. According to Wikipedia: The underlying basis for obtaining stanines is that a normal distribution is divided into nine intervals, each of ... [Read more...]

Summary: A new function in the WRS package compares many quantiles of two distributions simultaneously while controlling the overall alpha error. When comparing data from two groups, approximately 99.6% of all psychological research compares the central tendency (that is a … Continue reading → [Read more...]

Although there is a weighted.mean function in R, so far I couldn’t find a implementation of weighted.var and weighted.t.test – here they are (the weighted variance is from Gavin Simpson, found on the R malining list): ?View Code RSPLUS# weighted … Continue reading → [Read more...]

Recently I started to build a new package for R containing Wilcox’ collection of functions for robust statistics. Wilcox provides 700+ functions for robust statistics, including: robust correlations (e.g. percentage bend correlation) robust measures of location and mean differences (e.g. … Continue reading → [Read more...]