PYM013 LAS VARIEDADES DEL NUMISMÁTICO

Leyendo el discurso inaugural de la LXI Convención Numismática Internacional, reproducido en el El Boletín Numismático No. 248 (Julio - Septiembre 2015) de la Sociedad Numismática de México, A.C., el Lic. Juan Cristóbal Díaz Negrete hace una de las descripciones más completas y, a la vez, simples de las diferentes variedades del homo numismáticus con la que yo me haya topado:

 "(...) algunos apreciarán en las piezas sus cualidades artísticas y estilísticas; otros sus funciones económicas (como son su valor y su circulación); otros más se detendrán a reflexionar en torno a las condiciones históricas en que nacieron y se utilizaron; no faltará quienes se apasionen con los métodos de fabricación y los materiales empleados en ellas; y desde luego, estará presente, como siempre, el ojo sensible, educado e inquisitivo del buscador de variedades."

Parafraseando a Darwin, la máxima "de minimis lex non curat" no aplica al numismático, la numismática es materia de "pequeñeces".

PYM012 R GRAPH ESSENTIALS - REVIEW

The following is a review on the book R Graph Essentials, by David Lillis, that I volunteered to do some time ago and that I guess is by now way over due.

R Graph Essentials consists of four chapters:

1. Base graphics in R: plot()
2. Advanced functions in base graphics
3. Mastering the qplot function
4. Creating graphs with ggplot

The author is clear about one thing, this book is not an introduction in R. There is something odd about this though. Even when indeed the book presupposes a basic knowledge of the R language at some points very basic use of R is explained with great detail and, in some other cases, some not so basic characteristics of the language are taken by granted.

I general, I can say that this is a well written and brief book that provides clear explanations and useful reference material and that can be very useful as reference material for practical advice on making (basic) graphs in R. If you are looking for more help on making complex graphs, e.g. maps or dynamic graphs, this is not a book for you.

This is also not a book for someone who is looking for practice exercises. All the explanations, however, are guided by clear and very complete examples in which the author usually points out most of the problems usually faced in practice.

Considering this is an introductory book to graphs in R, still I lacked an explanation on the differences among the three basic graph "paradigms" available in R. Also, I think the reader with more complex needs would benefit with some references to more advanced material.

Last time I checked the book was priced at 14.99 GBP and, as far as I know, is available only in electronic format but has the advantage that it can be downloaded in various formats and the pdf format is not DRM protected which makes it very convenient for users that have to change plataforms regularly. The book can be purchased directly with the publisher at Packt Publishing.

@BOOK{lillis2014,
  title = {R Graph Essentials},
  publisher = {Packt Publishing},
  year = {2014},
  author = {Lillis, David Alexander},
  address = {Birmingham, UK},
}