Publications by Ralph
Generalized Linear Models – Poisson Regression
The Generalized Linear Model (GLM) allows us to model responses with distributions other than the Normal distribution, which is one of the assumptions underlying linear regression as used in many cases. When data is counts of events (or items) then a discrete distribution is more appropriate is usually more appropriate than approximating with a c...
2182 sym R (2762 sym/4 pcs) 4 img 4 tbl
R.NET
The R.NET project provides a mechanism for communicating with R from a .NET application. This appears to be a promising way to create simple interfaces to some of the functionality of R. Some examples of using R.NET can be found here and here. Related To leave a comment for the author, please follow the link and comment on their blog: Software...
706 sym
Getting rid of white space at the beginning and end of a string
There are situations where we are working with character strings extracted from various sources and it can be annoying when there is white space at the beginning and/or end of the strings. This whitespace can cause problems when attemping to sort, subset or various other common operations. The stringr package has a handy function str_trim (edited...
1206 sym R (193 sym/2 pcs) 2 tbl
LaTeX Typesetting –Basic Mathematics
LaTeX is very strong for typesetting mathematical equations. Fast Tube by Casper Other useful resources are provided on the Supplementary Material page. Related To leave a comment for the author, please follow the link and comment on their blog: Software for Exploratory Data Analysis and Statistical Modelling. R-bloggers.com offers daily e-ma...
599 sym 2 img
Scatter plots with images
Edward Tufte has written extensively on the presentation of data covering good and bad practice. He has made a number of suggestions for adaptations of regularly used graph types to assist with the interpretation and understanding of data. One idea for enhancing scatter plots covered in Tufte’s book Beautiful Evidence is the use of images in pl...
1366 sym
Cricket All Round Performances
In cricket a player who can perform well with both the bat and bowl is a great asset for any team and across the history of international cricket there have been a number of cricketers that hall into this bracket. It is difficult to specify a set of criteria to determine whether a player can be described as an all-rounder. To compare the performa...
2064 sym
Tikz Introduction
The pgf drawing package for LaTeX provides facilities for drawing simple of complicated pictures within a LaTeX document. There are many options available within the package and in this post we consider some of the basics to get up and running. Fast Tube by Casper As with all LaTeX documents we need to select a document class and include some pre...
1830 sym R (281 sym/6 pcs) 2 img
Tikz Nodes
Nodes are used in tikz to place content in a picture as part of a LaTeX document. Fast Tube by Casper When creating a tikz picture the origin is assumed to be at (0,0) and objects are placed with positioning relative to the origin on the picture. If we wanted to add a grid with lines from -3 to +3 in both the horizontal and vertical axes then we ...
1490 sym R (194 sym/5 pcs) 2 img
Tikz absolute positioning
When working with a tikz drawing within LaTeX document we might want to locate an object using an absoute position on the page rather than leaving LaTeX to make the decision for us. The use of nodes and the current.page label in conjunction with some other parameters attached to the tikz drawing will allow us to achieve the absolute positioning o...
1118 sym R (108 sym/1 pcs)
Surfaces in ternary plots
In mixture experiments there is a constraint that the variables are the proportions of components that are mixed together with the consequence that these proportions sum to one. When fitting regression models to data from mixture experiments we may be interested in reprenting the fitted model with a surface plot. The constraint on proportions mea...
1724 sym R (1061 sym/5 pcs) 2 img 5 tbl