1. Writing for Computer Science 7. Algorithms 8. Editing 2008. 05. 23 Cho, Ho-Gi GNU OSLab

2. Writing for Computer Science 2 Contents 7. Algorithms  Presentation of algorithms  Formalisms  Level of detail  Figures  Environment of algorithms  Performance of algorithms  Asymptotic complexity 8. Editing  Consistency  Style  Proofreading  Choice of word-processor  An editing checklist

3. GNU OSLabWriting for Computer Science 3 Performance of algorithms  Basis of evaluation Where algorithms are being compared, specify not only the environment but also the criteria used for comparison. Are the algorithms being compared for functionality or speed? Is speed to be examined asymptotically or for typical data? Is the data real or synthetic? A comparison should have a realistic basis  Processing time Time depends on factors such as CPU speed, cache sizes, system load, and hardware dependencies such as prefetch strategy. Times based on a mathematical model rather than on experiment should be clearly indicated as such. 7. Algorithms

4. GNU OSLabWriting for Computer Science 4  Memory and disk requirements It is often possible to trade memory requirements against time, not only by choice of algorithm but also by changing the way disk is used and memory is accessed.  Disk and network traffic Because of the sophistication of current disk drives and the complexity of their interaction with CPU and OS, exact mathematical descriptions of algorithm behavior are unattainable; broad approximations are often the only manageable way of describing disk performance. 7. Algorithms

5. GNU OSLabWriting for Computer Science 5 Asymptotic complexity  Define : Big-O notation a function f(n) is said to be O(g(n))-that is, g(n) is an upper bound of f(n)-if for some constants c and k we have f(n) ≤ c·g(n) for all n>k to mean the complexity rather than an upper bound on the complexity  Define : Theta-Θ notation if f(n) is O(g(n)) and g(n) is O(f(n))  Define : Omega-Ω notation a function f(n) is said to be Ω(g(n))-that is, g(n) is an lower bound of f(n)-if for some constants c and k we have f(n) ≥ c·g(n) for all n>k to mean the complexity rather than an lower on the complexity 7. Algorithms n n2n2 logn x y

6. GNU OSLabWriting for Computer Science 6 8. Editing Thesis concepts background logical flow research or experiments editing The difference between a weak writer and a strong writer is often not the ability to write fluently, but the effort taken to diligently edit and revise. paper or publication paper or publication 8. Editing … …

7. GNU OSLabWriting for Computer Science 7 Consistency  Much of editing consists of checking the document for errors that fall under the heading of consistency (or lack of it). use the checklist on page 134 effective editing exercise is to pretend to be a reader  The ordering too may need to be reconsidered once the paper is complete  For many papers, then, editing leads to excision of text cutting will improve the quality edit for brevity and balance 8. Editing

8. GNU OSLabWriting for Computer Science 8 Style  Keep in mind the basic aim, which is to make the paper clear  Most journals have a preferred style for elements such as references, figure numbering, spelling, table layout, and capitalization. 8. Editing

9. GNU OSLabWriting for Computer Science 9 Proofreading  There is no excuse for a report that contains spelling errors displaying not only your inability to spell, but also your casual attitude  A common error of mine is, when intending to type a word, to instead type some other word that shares a few initial letters. “being” for begin”, “form” for “from”, “relation” for “relative”,….  Check for errors in tense and in number, that is, in the use of plural and singular form  Important to check the bibliography format should be consistent and each reference should include enough information to allow readers to locate it  avoid widows and orphans

10. GNU OSLabWriting for Computer Science 10 if the last line of a paragraph contains only a single, short word, that line is a widow when the last line prior to a heading is by itself at the top of a page, or a heading or the first line of the following paragraph are alone at the bottom of a page, that line is an orphan

11. GNU OSLabWriting for Computer Science 11 Choice of word-processor  The choice is dictated by availability, but also by how well the available word-processors cope with the demands of authoring.  Microsoft Word and Web page visual or WYSIWYG 1) style for first drafts  LaTex compiler style for technical writing 1) What you see is what you get