**Numerical Recipes** is the generic title of a series of books on algorithms and numerical analysis by William H. Press, Saul A. Teukolsky, William T. Vetterling and Brian P. Flannery. In various editions, the books have been in print since 1986. The most recent edition was published in 2007. In 2015 Numerical Recipes sold its historic two-letter domain name nr.com and became `numerical.recipes`

instead.

The *Numerical Recipes* books cover a range of topics that include both classical numerical analysis (interpolation, integration, linear algebra, differential equations, and so on), signal processing (Fourier methods, filtering), statistical treatment of data, and a few topics in machine learning (hidden Markov model, support vector machines). The writing style is accessible and has an informal tone. The emphasis is on understanding the underlying basics of techniques, not on the refinements that may, in practice, be needed to achieve optimal performance and reliability. Few results are proved with any degree of rigor, although the ideas behind proofs are often sketched, and references are given. Importantly, virtually all methods that are discussed are also implemented in a programming language, with the code printed in the book. Each version is keyed to a specific language.

According to the publisher, Cambridge University Press, the *Numerical Recipes* books are historically the all-time best-selling books on scientific programming methods. In recent years, *Numerical Recipes* books have been cited in the scientific literature more than 3000 times per year according to ISI Web of Knowledge (e.g., 3962 times in the year 2008).

The first publication was in 1986 with the title,”Numerical Recipes, The Art of Scientific Computing,” containing code in both Fortran and Pascal; an accompanying book, “Numerical Recipes Example Book (Pascal) was first published in 1985. (A preface note in “Examples" mentions that the main book was also published in 1985, but the official note in that book says 1986.) Supplemental editions followed with code in Pascal, BASIC, and C. *Numerical Recipes* took, from the start, an opinionated editorial position at odds with the conventional wisdom of the numerical analysis community:

However, as it turned out, the 1980s were fertile years for the "black box" side, yielding important libraries such as BLAS and LAPACK, and integrated environments like MATLAB and Mathematica. By the early 1990s, when Second Edition versions of *Numerical Recipes* (with code in C, Fortran-77, and Fortran-90) were published, it was clear that the constituency for *Numerical Recipes* was by no means the majority of scientists doing computation, but only that slice that lived *between* the more mathematical numerical analysts and the larger community using integrated environments. The Second Edition versions occupied a stable role in this niche environment.

By the mid-2000s, the practice of scientific computing had been radically altered by the mature Internet and Web. Recognizing that their *Numerical Recipes* books were increasingly valued more for their explanatory text than for their code examples, the authors significantly expanded the scope of the book, and significantly rewrote a large part of the text. They continued to include code, still printed in the book, now in C++, for every method discussed. The Third Edition was also released as an electronic book, eventually made available on the Web for free (with limited page views) or by paid or institutional subscription (with unlimited page views).

The code listings are copyrighted and commercially licensed by the *Numerical Recipes* authors. One early motivation for the GNU Scientific Library was that a free library was needed as a substitute for *Numerical Recipes*.

Another line of criticism centers on the coding style of the books, which strike some modern readers as "Fortran-ish", though written in contemporary, object-oriented C++. The authors have defended their very terse coding style as necessary to the format of the book because of space limitations and for readability.

The books differ by edition (1st, 2nd, and 3rd) and by the computer language in which the code is given.

*Numerical Recipes. The Art of Scientific Computing, 1st Edition*, 1986, ISBN 0-521-30811-9. (FORTRAN and Pascal)
*Numerical Recipes. The Art of Scientific Computing, 3rd Edition*, 2007, ISBN 0-521-88068-8. (C++ code)
*Numerical Recipes in C. The Art of Scientific Computing, 2nd Edition*, 1992, ISBN 0-521-43108-5.
*Numerical Recipes in Fortran. The Art of Scientific Computing, 2nd Edition*, 1992, ISBN 0-521-43064-X.
*Numerical Recipes in Fortran 90. The Art of Parallel Scientific Computing, 2nd Edition*, 1996, ISBN 0-521-57439-0.
*Numerical Recipes in Pascal. The Art of Scientific Computing, 1st Edition*, 1989, ISBN 0-521-37516-9.
The books are published by Cambridge University Press.