R Programming

Experimental Design: Problem Set

June 21, 2012 | Al-Ahmadgaid Asaad

QUESTIONSThe tensile strength of Portland cement is being studied. Four different mixing techniques can be used economically. The following data have been collected: MixingTechniques Tensile Strength (lb/in­­2) 1 3129 3000 2865 2890 2 3200 3300 2975 3150 3 2800 2900 3985 3050 4 2600 2700 2600 2765 Test the hypothesis that mixing techniques affect the strength of the cement. Use $\alpha=0.05$.Construct a graphical display as described in Section 3...
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Text Mining to Word Cloud App with R

May 13, 2012 | CloudStat

Here is a simple application to transform text into a beautiful word cloud, Text Mining to WordCloud. The purpose is to find out the highest frequency word in a certain text. It is an app built with R language, the source code is attached at the end of... [Read more...]

R Tips: lots of tips for R programming

April 26, 2012 | Yanchang Zhao

by Yanchang Zhao, RDataMining.com There are more than 100 R tips at http://pj.freefaculty.org/R/Rtips.html, which provide quick examples to small challenges in everyday R programming, especially for users switching from other languages to R. There is also a .PDF version for … Continue reading → [Read more...]

Tutorial: Using plot() function

April 19, 2012 | alstated

Hello Readers! This is my first post as a member ofR-bloggers. In this post I'm going to talk about the basic plotting in R, fortwo dimensional. This is a tutorial for beginners in R.To begin with, let's define a vector first. Say wehave vector x, whic...
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Cochran Q Test for k related samples in R

February 1, 2012 | alstated

To run the Cochran Q Test in R, we need to download the package of it first, since it is not built-in in R. The name of the package is RVAideMemoire authored by Maxime Hervé. Here's how to do it.Codes:Here we are installing the package named RVAideMem...
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Example: Two Sample t-Test

January 31, 2012 | Al-Ahmadgaid Asaad

The recovery time (in days) is measured for 10 patients taking a new drug and for 10 different patients taking a placebo. We wish to test the hypothesis that the mean recovery time for patients taking the drug is less than for those taking placebo. The...
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Example: One Sample t-Test

January 31, 2012 | Al-Ahmadgaid Asaad

Using the stack loss dataset, test the hypothesis that the mean of the stackloss is equal to 20 versus a two-sided alternative. Solution:Codes:Output:Interpretation: With the p-value greater than the level of significance alpha at 0.05, then we la...
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CloudStat School – The Introduction

January 1, 2012 | CloudStat

CloudStat School is a not yet released open source project. The objective is to create an interactive R Learning Platform. The best way to learn R programming is doing while learning. In CloudStat School, you will see a console box at your top left han... [Read more...]

data.frame objects in R (via “R in Action”)

December 18, 2011 | Tal Galili

The followings introductory post is intended for new users of R.  It deals with R data frames: what they are, and how to create, view, and update them. This is a guest article by Dr. Robert I. Kabacoff, the founder of (one of) the first online R tutorials websites: Quick-R.  ... [Read more...]

Prime Number in R Language (CloudStat)

November 28, 2011 | CloudStat

A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. R Language Code The Prime Function prime = function(n){   n = as.integer(n)   if(n __ 1e8) stop(“n too large”)   primes = re...
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Sweave and pgfSweave in LyX 2.0.x (experimental)

May 25, 2011 | Yihui Xie

bout half a year ago, I wrote a post on the configuration of (pgf)Sweave and LyX, which was intended to save us some efforts in going through all the details during the configuration. Now many things have changed: LyX 2.0 has internal support for Sweave, and fortunately I have been ... [Read more...]

formatR update (0.1-6)

January 6, 2011 | Yihui Xie

A new version of the formatR package is available on CRAN now (binary packages are still on the way). There are three major updates: the inline comments will also be preserved in most cases (in earlier versions, only single lines of comments are preserved) tidy.source() gained a new argument ... [Read more...]

formatR update (0.1-5)

December 3, 2010 | Yihui Xie

he formatR package has been silent for quite a few months now. Recently I’ve been moving my old packages from R-Forge to GitHub, and I finally killed several things on my TODO list. In the past, I made an awkward decision to let formatR depend on the animation package, ... [Read more...]

Rd2roxygen: Convert Rd to roxygen documentation

December 1, 2010 | Yihui Xie

must admit that I have been tired of maintaining my R packages for a long time, and the main reason is I feel really uncomfortable with writing R documentations (Rd). The required structure of an R package mainly includes two directories R and man — the former for the R source ... [Read more...]
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