Re: WolframAlpha[] give results but not parse!
- To: mathgroup at smc.vnet.net
- Subject: [mg114559] Re: WolframAlpha[] give results but not parse!
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Tue, 7 Dec 2010 06:49:36 -0500 (EST)
But WolframAlpha["solve dy/dt=2y(1-y)", "MathematicaForms"] only gives Mathematica syntax for the _result_ of the DSolve command, still not the input. If the WolframAlpha server is parsing my input sufficiently to understand and evaluate it, why is it not returning, also, the corresponding Mathematica DSolve input? On 12/6/2010 6:13 AM, Maxim wrote: > On Dec 4, 5:15 am, Murray Eisenberg<mur... at math.umass.edu> wrote: >> In Mathematica 8.0, the following gives the expected explicit >> solution, graphs, etc.: >> >> WolframAlpha["solve dy/dt=2y(1-y)"] >> >> It even tells me the interpretation as "solve y'(t)=2y(1-y)". Of >> course, just using input >> >> =solve dy/dt=2y(1-y) >> >> gives the same results. >> >> However, the following (as well as the Ctrl= input form for it) gives >> no Mathematica translation of the input: >> >> WolframAlpha["solve dy/dt=2y(y-1)","MathematicaParse"] >> >> It is surprising that WolframAlpha "understands" what I asked but >> cannot actually tell me in Mathematica syntax the same thing! >> >> Or am I missing something? >> >> -- >> Murray Eisenberg Internet: mur... at math.umass.edu >> Mathematics& Statistics Dept. Voice: 413-545-2859 (W) >> University of Massachusetts 413-549-1020 (H) >> Amherst, MA 01003 Fax: 413-545-1801 > > This is a bit of an implementation detail, but (simplifying things > somewhat) the query goes through the W|A parser first and sometimes > the result of the parse is an expression that can be evaluated on its > own on the client side. In that case you get "MathematicaParse". Other > times the result of the parse is an intermediate form which invokes W| > A scanners. The scanners generate the pods and the pods can contain > "Mathematica plaintext output" fields. You can extract those by doing > WolframAlpha["solve dy/dt=2y(1-y)", "MathematicaForms"]. > > Maxim Rytin > m.r at inbox.ru > -- 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