Re: Re: Better WorldPlot data?

*To*: mathgroup at smc.vnet.net*Subject*: [mg13103] Re: [mg13090] Re: Better WorldPlot data?*From*: Wouter Meeussen <eu000949 at pophost.eunet.be>*Date*: Tue, 7 Jul 1998 03:44:08 -0400*Sender*: owner-wri-mathgroup at wolfram.com

hi all, please take *speed* into consideration. Plotting charts is very slow even now. I would be more charmed with a reduced data set in which the common borders between countries would be somehow linked ; this would enable me to generate deformed charts where the area of a country is proportional to its *population* (or any other property I want to visualise). I've seen maps like that, and they were marvellous. It would enable us to treat the dataset as more than a set of lines, more like a graph (with all goodies in the DiscreteMath package applicable) to show my constructive attitude (:-), here are a few lines of code that enable you to plot great arcs : **************************************************************************** <<Miscellaneous`WorldPlot` <<Miscellaneous`CityData` m2r[z_]:=N[z/60/180*Pi] r2m[z_]:=N[z/Pi*60*180] greatcircle[tok_List,hon_List,n_Integer]:= Module[{t=tok[[2]],h=hon[[2]]}, If[Abs[t-h]<=180*60, {Table[{r2m at Li[m2r@\[Lambda]x,m2r at tok,m2r at hon],\[Lambda]x},{\[Lambda]x,h , t,(t-h)/n}]//N}, {Table[{r2m at Li[m2r@\[Lambda]x,m2r at tok,m2r at hon],\[Lambda]x},{\[Lam bda]x, Max[t,h],180*60,(180*60-Max[t,h])/n}]//N, Table[{r2m at Li[m2r@\[Lambda]x,m2r at tok,m2r at hon],\[Lambda]x},{ \[Lambda]x,-180*60,Min[t,h],(Min[t,h]+180*60)/n }]//N }]] hon=CityData["Honolulu", CityPosition]//ToMinutes ist=CityData["Istanbul", CityPosition]//ToMinutes rom=CityData["Rome", CityPosition]//ToMinutes Show[{wpm,WorldGraphics[{ Hue[0.0], Thickness[0.005],Line/@greatcircle[hon,rom,40], Hue[0.5], Line/@greatcircle[hon,ist,40] }] }] **************************************************************************** *************** wouter. At 03:37 5-07-98 -0400, David Reiss wrote: >In article <6nc6qv$fb1 at smc.vnet.net>, Sigurd Tjelmeland <sigurd at imr.no> >wrote: > >> > >> >> Does anyone know of any better WorldData databases than the one that >> comes with Mathematica? There are two few points, and the countries get >> a rather ugly shape. For the geographical area in which I work >> (North-east Atlantic) I took data from the GEBCO base and transformed >> to Mathematica lists. I am interested in Mathematica lists around the >> globe for areas north of 50 N. My lists are of course available for >> those interested. >> >> Sigurd Tjelmeland >> >> Institute of Marine Research >> Bergen, Norway >> >> sigurd at imr.no > >I would be very heplful to Mathematica users if you would post your >datasets to MathSource (www.mathsource.com). I think that WorldPlot >could be made more usesful if the database for it were more up to >date, of higher resolution, and generally more detailed. If anyone >else has other data sets for use in WorldPlot, MathSource would welcome >them with open arms (files?). > >Also, could you describe the GEBCO base further? > >Thanks, > >David Reiss > >("editor-at-large" for MathSource) > >-- >David Reiss >dreissNOSPAM at nospam.earthlink.net >http://home.earthlink.net/~dreiss >To send personal email, remove the words "nospam" and "NOSPAM" from the >email address > > Dr. Wouter L. J. MEEUSSEN w.meeussen.vdmcc at vandemoortele.be eu000949 at pophost.eunet.be