If you ever had to program a complicated numerical algorithm, such as SVD decomposition, Bessel functions, eigensystems or Fourier transform, you will know how useful this book is. All those problems, and many others, are presented and the full BASIC code of a routine, which solves it, is given. This book is an issue for "Numerical recipes in FORTRAN", that brings the codes in FORTRAN 77 and also the mathematical theory behind the routines. There are versions of this issue also for Pascal and C++. If you need any routine, you just have to "cut and paste" it from the book into your program. Don't left to look "Numerical Recipes in FORTRAN", which is the mother of the whole collection.