The latest version of the devtools package on CRAN (version 1.12.0) has a bug that causes issues with the installation of package dependencies on Windows, which usually manifest as errors during the installation of GitHub packages stating some dependency (e.g. stringi or dplyr or htmltools, etc. package missing). The issue is described in various bug reports and was fixed in December 2016 (devtools issue #1409). However, as of March 2017, this bug fix has not propagated to the version of devtool on CRAN yet. The easiest solution is to use the fixed devtools from GitHub (this specific commit fixes the problem) for the installation of GitHub packages. Windows may not allow installation of a GitHub version of devtools using devtools (because it cannot overwrite the loaded package), in which case the easiest approach is to use the build_github_devtools function whic


Wolfram Alpha API from R

The attached code file provides an easy basic interface to the Wolfram Alpha API. Inspired by the wolframalpha module available for Python.


Initialize client

View analysis.Rmd
title output
Analysis test
# This code chunk simply makes sure that all the libraries used here are installed, it will not be shown in the report (notice echo = FALSE).
packages <- c("readxl", "knitr", "tidyr", "dplyr", "ggplot2", "plotly")
if ( length(missing_pkgs <- setdiff(packages, rownames(installed.packages()))) > 0) {
  message("Installing missing package(s): ", paste(missing_pkgs, collapse = ", "))

##Installation information for R with GTK+

###Windows Install the newest version of R. Additionally, I highly recommend R-Studio for working with R regularly (but the basic command line will work just fine for most applications). Once R is installed, you can install GTK directly from within R (details below). In short:

  1. From the R command line (e.g. in R-Studio), install the RGtk2 package by running: install.packages("RGtk2", depen=T)
    This might fail with the warning that package ‘RGtk2’ is not available (for R version xxx) if your version of R has been released very recently. If so, just run install.packages("RGtk2", depen=T, type="source") instead to install the RGtk2 package directly from its source code (this might take a few mi
View nPlot_with_y2Axis.R
library(rjson) # required for overwrite
# load rCharts and extend Nvd3 object to allow y2Axis parameters (not implemented in rCharts yet)
nPlot <- function(x, data, ...){
Nvd3mod <- setRefClass('Nvd3mod', contains = 'Nvd3', methods = list(
initialize = function(){
LIB <<- get_lib('nvd3') # library name and url to parent library
templates$script <<- 'NVD3.html' # chart template to include y2Axis-
params <<- c(params, list(y2Axis = list()))
View NVD3.template.html
<script type='text/javascript'>
function draw{{chartId}}(){
var opts = {{{ opts }}},
data = {{{ data }}}
var data = d3.nest()
View Isotope labeling and growth.ipynb
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