On 01/27/2010 01:30 PM, Aaron W. Hsu wrote: > On Tue, 26 Jan 2010 21:22:43 -0500, <EilertO at aol.com> wrote: > >> One question: If justification is on a paragraph by paragraph >> basis, how >> is it possible that all paragraphs share the same common right margin >> position? In my simplistic way (read: uninformed) it sounds like >> each paragraph >> could have a different width??? This is probably not true, but help >> me!!!! > > Justification is a matter of calculating the best spacing of lines in > a paragraph to fit within some column width. This usually boils down > to some formula of some kind. The question is what information is > passed to and used by that formula for the calculation. Some > applications justify on a line by line basis. That means that given a > paragraph on the page, it will have a set of lines where it will be > usually printed without justification. Once you enable justifcation, > these lines are then spaced individually to make them fit within the > column. > > TeX has a more sophisticated method of formatting the paragraph > because it takes into account the entire paragraph when doing the work > (read, using the formula). Once you go line by line, you lose the > information that might have changed your choice slightly if you could > bring or push words on different lines to other lines. TeX allows you > to do this. > > For example, in a line based justifier, it can only work with the > words that it has on that line, but say that you could get a slightly > "better" justification if you took a small word from the line before > it and used it in the line you are currently trying to justify. This > could happen, or vice versa, where it might be better to shift a word > down from the previous line and so forth. When you have the whole > paragraph rather than just a single line with which to work, you can > do these sorts of transformations, whereas you cannot do them if you > only work with each line by itself. > > This is my understanding of how the formulas and code work behind the > scenes. If someone can clarify or correct me where I am wrong, that > would probably be helpful to us all. Two things:
1. It's easy to say that a line-based justification only works per line, but in a character stream, what is a line? There has to be some initial attempt at fitting to a line, then adjustments, so the quality comes down to the flexibility of those adjustments. 2. It's also a good idea to take off the rose-colored glasses about TeX. I use it on a daily basis, and in a tabular environment, some quite ugly output happens even with all the advanced features of word and character placement that TeX has to offer. Greg
