Liebe Freundinnen und Freunde neuer Mathematicafähigkeiten,Mathematica bietet umfangreiche Geodaten, darunter 164'601 Einträge in CityData[].
Ortsnamen wiederholen sich auf der Erde und man kann fragen, in wievielen verschiedenen Ländern derselbe Ortsname vorkommt; ein Beispiel - leider nicht mit Mathematica herausgefunden - ist der Name "Santa Maria":
In[1]:= Tally[EntityClass["City", "Name" -> "Santa Maria"]["Country"]]
Out[1]= {{Entity["Country", "Brazil"],
1}, {Entity["Country", "UnitedStates"],
2}, {Entity["Country", "Philippines"],
11}, {Entity["Country", "Peru"],
1}, {Entity["Country", "CapeVerde"],
1}, {Entity["Country", "Chile"], 1}, {Entity["Country", "Colombia"],
2}, {Entity["Country", "Paraguay"],
1}, {Entity["Country", "Panama"],
1}, {Entity["Country", "Honduras"],
2}, {Entity["Country", "CostaRica"],
1}, {Entity["Country", "Nicaragua"], 1}}
In[5]:= (* Anzahl der Länder *)
Length[%1]
Out[5]= 12
da werden 12 Länder gemeldet.
Man kann weiter fragen, wie die über die Anzahl der Länder graduierten
Maxima aussehen, also welcher Name erscheint am meisten unter den Namen,
die in n Ländern auftreten. Wie kann man diese Frage in Mathematica
stellen?
Nach einer Reihe trister Anzeigen, die besagten, dass die Daten erneut geladen werden und nach überaus wüsten Verarbeitungszeiten ohne Ergebnis wurde der Datensatz nach PostgreSQL importiert, wo das Query
select Q2.name, Q2.cities, Q2.countries from ( select q1.name, q1.cities, q1.countries, rank() over ( partitionby q1.countries order by q1.cities desc) as rk from ( select q.name, sum( q.count) as cities, count(*) as countries FROM ( select c.name, c.country, count(*) from joey.citydata c group by c.name, c.country ) as Q group by Q.name order by cities desc, countries desc ) as Q1 ) as Q2 where Q2.rk = 1 order by Q2.countries desc; in Sekundenschnelle die Antwort /* " SantaMaria"; 26;13 " SanPedro"; 24;12 " Victoria"; 24;12 " SanJose"; 28;11 " SantaCruz"; 28;11 " SanMiguel"; 28;10 " SanFrancisco";27;9 " SanJuan"; 20;8 " Richmond"; 30;7 " Wellington"; 17;6 " Cambridge"; 18;5 " Salem"; 28;4 " Clinton"; 28;3 " Springfield"; 25;2 " Franklin"; 28;1 */gibt. Aha - demnach kommt 'SantaMaria' in 13 Ländern vor, nicht in 12. Das dreizehnte Land ist Rumänien, woran das nächste Problem sichtbar wird. Das dortige 'SantaMaria' liegt in der Region (Regierungsbezirk) 'Botosani':
In[12]:= CityData[{All, "Botosani", "Romania"}]
Out[12]= {Entity["City", {"Botosani", "Botosani", "Romania"}],
Entity["City", {"Dorohoi", "Botosani", "Romania"}],
Entity["City", {"Flamanzi", "Botosani", "Romania"}],
Entity["City", {"Darabani", "Botosani", "Romania"}],
Entity["City", {"Saveni", "Botosani", "Romania"}],
Entity["City", {"Vorona", "Botosani", "Romania"}],
Entity["City", {"Copalau", "Botosani", "Romania"}],
Entity["City", {"Ungureni", "Botosani", "Romania"}],
Entity["City", {"Albesti", "Botosani", "Romania"}],
Entity["City", {"Corni", "Botosani", "Romania"}],
Entity["City", {"MihailEminescu", "Botosani", "Romania"}],
Entity["City", {"Hudesti", "Botosani", "Romania"}],
Entity["City", {"Frumusica", "Botosani", "Romania"}],
Entity["City", {"Stefanesti", "Botosani", "Romania"}],
Entity["City", {"Trusesti", "Botosani", "Romania"}],
Entity["City", {"SuliTa", "Botosani", "Romania"}],
Entity["City", {"Avrameni", "Botosani", "Romania"}],
Entity["City", {"Suharau", "Botosani", "Romania"}],
Entity["City", {"CoTusca", "Botosani", "Romania"}],
Entity["City", {"Bucecea", "Botosani", "Romania"}],
Entity["City", {"Tudora", "Botosani", "Romania"}],
Entity["City", {"Dersca", "Botosani", "Romania"}],
Entity["City", {"Havarna", "Botosani", "Romania"}],
Entity["City", {"Mihaileni", "Botosani", "Romania"}],
Entity["City", {"Baluseni", "Botosani", "Romania"}],
Entity["City", {"Vladeni", "Botosani", "Romania"}],
Entity["City", {"Lunca", "Botosani", "Romania"}],
Entity["City", {"Cristesti", "Botosani", "Romania"}],
Entity["City", {"Vorniceni", "Botosani", "Romania"}],
Entity["City", {"RachiTi", "Botosani", "Romania"}],
Entity["City", {"Curtesti", "Botosani", "Romania"}],
Entity["City", {"Sendriceni", "Botosani", "Romania"}],
Entity["City", {"Ibanesti", "Botosani", "Romania"}],
Entity["City", {"Durnesti", "Botosani", "Romania"}],
Entity["City", {"Corlateni", "Botosani", "Romania"}],
Entity["City", {"Calarasi", "Botosani", "Romania"}],
Entity["City", {"RadauTiPrut", "Botosani", "Romania"}],
Entity["City", {"VarfuCampului", "Botosani", "Romania"}],
Entity["City", {"Cristinesti", "Botosani", "Romania"}],
Entity["City", {"Hlipiceni", "Botosani", "Romania"}],
Entity["City", {"Manoleasa", "Botosani", "Romania"}],
Entity["City", {"HiliseuHoria", "Botosani", "Romania"}],
Entity["City", {"GeorgeEnescu", "Botosani", "Romania"}],
Entity["City", {"Gorbanesti", "Botosani", "Romania"}],
Entity["City", {"Todireni", "Botosani", "Romania"}],
Entity["City", {"BroscauTi", "Botosani", "Romania"}],
Entity["City", {"Vlasinesti", "Botosani", "Romania"}],
Entity["City", {"Paltinis", "Botosani", "Romania"}],
Entity["City", {"Stauceni", "Botosani", "Romania"}],
Entity["City", {"Prajeni", "Botosani", "Romania"}],
Entity["City", {"Roma", "Botosani", "Romania"}],
Entity["City", {"Dangeni", "Botosani", "Romania"}],
Entity["City", {"SantaMaria", "Botosani", "Romania"}],
Entity["City", {"UnTeni", "Botosani", "Romania"}],
Entity["City", {"Rauseni", "Botosani", "Romania"}],
Entity["City", {"Mileanca", "Botosani", "Romania"}],
Entity["City", {"Pomarla", "Botosani", "Romania"}],
Entity["City", {"Dobarceni", "Botosani", "Romania"}],
Entity["City", {"Nicseni", "Botosani", "Romania"}],
Entity["City", {"Stiubieni", "Botosani", "Romania"}],
Entity["City", {"Draguseni", "Botosani", "Romania"}],
Entity["City", {"Leorda", "Botosani", "Romania"}],
Entity["City", {"Mihalaseni", "Botosani", "Romania"}],
Entity["City", {"Hanesti", "Botosani", "Romania"}],
Entity["City", {"Viisoara", "Botosani", "Romania"}],
Entity["City", {"Ripiceni", "Botosani", "Romania"}],
Entity["City", {"Vaculesti", "Botosani", "Romania"}],
Entity["City", {"Braesti", "Botosani", "Romania"}],
Entity["City", {"Romanesti", "Botosani", "Romania"}],
Entity["City", {"Cordareni", "Botosani", "Romania"}],
Entity["City", {"Concesti", "Botosani", "Romania"}],
Entity["City", {"Mitoc", "Botosani", "Romania"}]}
ein glasklares "SantaMaria", in der Anzeige erscheint es als
"Santa-Maria", siehe bitte das beigelegte Bildchen, aber weder mit dem
normalisierten Namen noch mit dem Anzeigenamen wird's in Rumänien gefunden:
In[13]:= Tally[EntityClass["City", "Name" -> "Santa-Maria"]["Country"]]
Out[13]= {}
In[14]:= Tally[EntityClass["City", "Name" -> "SantaMaria"]["Country"]]
Out[14]= {}
Mit den besten Grüssen
Udo.
Santa-Maria-Romania.jpg
Description: JPEG image
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