Linear computations" as used by Professor Dwyer applies to the computations involved in the solution of simultaneous linear equations and such allied problems as the evaluation of determinants, the calculation of the adjoint and the inverse of a matrix, and the solution of problems involving the characteristic equation.
Methods presented are ideal for use by operators of modern desk-type calculating machines. The method of computing square root on such machines is mentioned briefly. Considerable attention is given to computation with approximate numbers, and the associated errors. The subjects of determinants and matrices are introduced as needed; previous familiarity with these subjects is not required. The book is concluded with chapters entitled "Application to Statistics" and "Application to Non-Linear Problems."
The third chapter, "The Principles of Computational Design," stresses the need for computational methods that provide for the control of errors, minimize the recording and resetting, and are fast and easy. Professor Dwyer's methods of solving linear equations liw. up to his own standards. Provision is made for row checking wherever possible. The methods have been perfected through their repeated use with desk calculators, through being taught at the University of Michigan, and through Professor Dwyer's published articles on the subject.
Professor Dwyer is thoroughly familiar with the modern calculating machine and his courses in mathematical statistics are well received. Students in such courses at the University of Michigan perform their homework problems in a laboratory equipped with desk calculators. His methods have been tried and proved, and though used today in several aircraft companies and the country's leading laboratories, they deserve the wider publicity made possible by publication in book form.
The book is of text book style, amply fortified with examples, exercises, and references. It should be required reading for any desk calculating machine operator, as familiarity with it will pay dividends in accurate work and time saved. It is a must for supervisors of computer groups. Though no more than high school algebra is needed, the book would make a fine text for a course for college seniors majoring in mathematics at universities equipped with calculating machines. Some of the machine salesmen who, in trying to peddle their brand, consistently demonstrate accounting methods to computing groups, would do well to brush up on the latesl