Re: Re: annoying documentation in 6 (rant)
- To: mathgroup at smc.vnet.net
- Subject: [mg79179] Re: [mg79125] Re: annoying documentation in 6 (rant)
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Fri, 20 Jul 2007 03:29:56 -0400 (EDT)
- Organization: Mathematics & Statistics, Univ. of Mass./Amherst
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- Reply-to: murray at math.umass.edu
How did you discover the function Precedence? I tried searching for it in the Documentation Center and I got a set of 11 pages none of whose items, so far as I can see, includes that function. Moreover, evaluating "?Precedence" in a notebook just tells one that Precedence is in context System and is Protected -- nothing more and no link to a reference page! Moreover, exactly what do the values of Precedence indicate? For example, Precedence[Apply] Precedence[Map] 620 620 This doesn't say what Mathematica does if there's an Apply and a Map in an expression. And in any case, Precedence is of no use in trying to handle a special input form such as @@ or /@ -- which is the real issue! -- since Precedence signals a Syntax error in such cases. David Bailey wrote: > Murray Eisenberg wrote: >> Here's another shortcoming of the 6.0 Documentation Center organization >> (or lack thereof). >> >> When one uses special input forms (abbreviations), such as = and := and >> /. and @ and @@ and @@@ and /@, what is the order of precedence and what >> is the grouping when a single form appears several times in a row? >> >> In The Mathematica Book this was answered in an obvious place, namely, >> Section A.2, "Input Syntax", of the Appendix "Mathematica Reference Guide". >> >> Where is it in the Version 6.0 Documentation Center? After some >> considerable searching I found it in tutorial/InputSyntax. >> >> But at this point I cannot even reconstruct how I found it! I tried >> searching on "precedence" and "order of precedence". The first turns up >> nothing obviously useful. The second gave as the tenth entry "The Syntax >> of the Mathematica Language", which is a tutorial. And roughly a third >> to a half-way down in that tutorial says, >> >> The table in "Operator Input Forms" gives the complete >> ordering by precedence of all operators in Mathematica. >> >> The phrase 'Operator Input Forms' there has a link, finally, to the >> correct place in the tutorial (!!) InputSyntax. >> >> Another possible route to the same thing is from the home page of the >> Documentation Center, at the item "Syntax" in the first box "Core >> Language". The target is guide/Syntax. In that guide, near the bottom >> of the page, under "Tutorials", is a link to the aforementioned tutorial >> "The Syntax of the Mathematica Language" (which then requires spotting >> the further link to the relevant material). And in guide/Syntax there's >> another tutorial link, "Input Syntax", whose target is the desired >> end-point tutorial/InputSyntax. >> >> Such are the ways of the 6.0 Documentation Center -- and some of the >> intricacies and limitations of combining expository and tutorial >> presentations with reference materials. >> >> In the case at hand, I got there eventually. But after I did I felt >> like it shouldn't be so hard. (Maybe the younger generations are more >> adept or more patient at negotiating searches than I!) >> >> So: The more I use the Documentation Center, the more I like it and, >> at the same time, the more I miss The Mathematica Book (whether printed >> or electronic). >> >> David Bailey wrote: >> >>> Seriously, though, without a book for 6.0, the help topics absolutely >>> must be authoritative and complete. > Murray, > > I certainly agree - that table is very useful, but you can get at least > part of that information by using Precedence, e.g.: > > Precedence[Times] > > However, I don't know a function to get the associativity of the operators. > > David Bailey > http://www.dbaileyconsultancy.co.uk > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305
- References:
- Re: annoying documentation in 6 (rant)
- From: David Bailey <dave@Remove_Thisdbailey.co.uk>
- Re: annoying documentation in 6 (rant)
- From: David Bailey <dave@Remove_Thisdbailey.co.uk>
- Re: annoying documentation in 6 (rant)