Differential Equations Solutions 7

Differential Equations Solutions 7 - be generated for...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 4 Solutions: Design of Computer Programs: Writing Your Legacy CHALLENGE 4.1. See posteddoc.m on the website. CHALLENGE 4.2. Data that a function needs should be speciFed in variables, not constants. This is Fne; C is a variable. Code should be modular, so that a user can pull out one piece and substi- tute another when necessary. The program posted factors a matrix into the product of two other matrices, and it would be easy to substitute a di±erent factorization algorithm. On the other hand, there is considerable overhead involved in function calls, so each module should involve a substantial computation in order to mask this overhead. This is also satisFed; posted performs a signiFcant computation ( O ( mn 2 ) operations). Input parameters should be tested for validity, and clear error messages should
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: be generated for invalid input. The factorization can be performed for any matrix or scalar, so input should be tested to be sure it is not a string, cell variable, etc. Spaghetti code should be avoided. In other words, the sequence of instruc-tions should be top-to-bottom (including loops), without a lot of jumps in control. This is Fne, although there is a lot of nesting of loops. The names of variables should be chosen to remind the reader of their purpose. The letter q is often used for an orthogonal matrix, and r is often used for an upper triangular one, but it would probably be better practice to use uppercase names for these matrices. 17...
View Full Document

Ask a homework question - tutors are online