Re: Re: Re: Re: ListCurvePathPlot

*To*: mathgroup at smc.vnet.net*Subject*: [mg96039] Re: [mg96015] Re: [mg95995] Re: [mg95935] Re: [mg95909] ListCurvePathPlot*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Mon, 2 Feb 2009 06:22:01 -0500 (EST)*Organization*: Mathematics & Statistics, Univ. of Mass./Amherst*References*: <200901291058.FAA18253@smc.vnet.net> <200902010941.EAA22811@smc.vnet.net>*Reply-to*: murray at math.umass.edu

With the possible exception of the very earliest versions, I'm not sure that Mathematica was ever completely and authoritatively documented. And this is a problem hardly unique to Mathematica. Of course there IS authoritative documentation available, namely, what the Mathematica interpreter actually does! But I do agree that in the rush to get really, really, really useful new features out to users, the documentation has sometimes lagged behind. peter wrote: > doesn't this just underline the impression that Wolfram are dropping > the ball on documentation ? Doesn't matter how clever the programmers > or the users are - unless the product is authoritatively documented, > it is incomplete. > > Peter > > 2009/1/31 DrMajorBob <btreat1 at austin.rr.com>: >> Interesting? Yes. >> >> Useful? I don't see how! >> >> Bobby >> >> On Fri, 30 Jan 2009 04:44:00 -0600, Curtis Osterhoudt <cfo at lanl.gov> wrote: >> >>> The following is rather interesting. I think it (with some imagination) >>> conforms to the definition given in the Mathematica Documentation, but >>> it wasn't what I was expecting. >>> >>> data = Table[RandomReal[{-1.3, 1.2}]*{Cos[t], Sin[t]}, >>> {t, 0, 6*Pi - 2*(Pi/6), Pi/6.1}]; >>> >>> >>> {{0.25002688366379333, 0.}, {0.9356799430343185, >>> 0.5295589611737038}, >>> {0.10118796319464748, 0.16851424646497157}, >>> {-0.029188553024956546, -1.1332520553860652}, >>> {-0.23082153680912088, 0.4335135296822279}, >>> {0.7576710364167465, -0.48192811086842924}, >>> {0.9705776190593385, -0.05003046313427862}, >>> {1.0962492703177467, 0.5479411095599908}, >>> {0.6370536297044893, 0.9468064433345135}, {0.03136422751102095, >>> 0.4051894691695028}, {0.364963285556999, -0.7797519520786809}, >>> {-0.9341065689324766, 0.6640763628660812}, >>> {0.013137997466309304, -0.0013580598861936942}, >>> {-0.6906567258137415, -0.301834640354331}, >>> {0.566523954686374, 0.7549438704279434}, {0.07549928355009236, >>> 0.5831410479690148}, {0.4000794379862568, -0.9837423213746447}, >>> {0.24638452631107208, -0.19500664556832673}, >>> {1.1421844045687481, -0.17789046644213574}, >>> {0.11779527337621096, 0.04440716210668134}, >>> {-0.10502847445807519, -0.12589786231771516}, >>> {0.20288991501930384, 1.1133525098565278}, >>> {0.19075826931350767, -0.54838931166244}, {-0.013717694614866967, >>> 0.012056157937833439}, {0.8381916063026793, \ >>> -0.17515740827734855}, >>> {-0.7711479671903417, -0.24617764515949736}, >>> {0.5886009181985181, 0.6359230898649515}, {-0.2787870392560766, >>> -1.1813146432588384}, {-0.04025184234997148, 0.1382818883263678}, >>> {0.29420624689007885, -0.2867261088679789}, >>> {0.6823920131526263, -0.17971101963053693}, >>> {1.1400162086445282, 0.3002284190055794}, {-0.13739394197848387, >>> -0.13390072706458242}, {0.00505513032785771, >>> 0.017366483784624985}, >>> {0.10886543986338092, -0.4612995589701644}} >>> >>> ListCurvePathPlot[data, Axes -> False] >>> >>> --C.O. >>> >>> >>> >>> >>> >>> On Thursday 29 January 2009 03:58:55 David Park wrote: >>>> I don't understand the new ListCurvePathPlot, which the Help page says: >>>> "attempts to reconstruct smooth curves defined by the specified set of >>>> points." >>>> >>>> >>>> >>>> This plot routine also has the option: InterpolationOrder. And the word >>>> "Curve" appears not only in the name but repeatedly in the descriptions. >>>> But look at the following example: >>>> >>>> >>>> >>>> data = Table[ >>>> >>>> RandomReal[{.8, 1.2}] {Cos[t], Sin[t]}, {t, 0, 2 \[Pi] - 2 \[Pi]/6, >>>> >>>> 2 \[Pi]/6}]; >>>> >>>> ListCurvePathPlot[data, >>>> >>>> InterpolationOrder -> 3, >>>> >>>> Axes -> False] >>>> >>>> >>>> >>>> I don't see anything "smooth" or "curvy" about the results! So it seems >>>> that these terms are a misdirection in understanding the use of the >>>> routine. >>>> It appears that what the routine actually does is reorder the points to >>>> give >>>> some simpler line (not curve) than the original set of points. But what >>>> is >>>> the criterion for this? Is this some well know computational geometry >>>> algorithm? Was InterpolationOrder included as an option by mistake? Did >>>> the >>>> implementation change from the original intention? What is the purpose >>>> of >>>> the routine? What is the relation of this and the spline functions? >>>> >>>> >>>> >>>> David Park >>>> >>>> djmpark at comcast.net >>>> >>>> <http://home.comcast.net/~djmpark> http://home.comcast.net/~djmpark/ >>>> >>>> >>> >>> >> >> >> -- >> DrMajorBob at longhorns.com >> >> > -- 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: Re: Re: ListCurvePathPlot***From:*peter <plindsay.0@gmail.com>