Dear all,
There really seem to be many exciting issues in spelling and in
detecting spelling errors. However, a more disturbing feature in
'eurodist' to me is that the distances seem to be wrong. There are
several cases where the triangle inequality is violated so that a trip
from A to B is shorter when you make a detour via X instead of going
directly (see require(fortunes); fortune("eurodist") for an example). A
quick look revealed that you can find such a shorter detour for 104 of
210 "distances" of 'eurodist'. There is no guarantee that these shortest
path distances would be correct, but at least they are metric.
Just for fun, here are the differences between actual eurodist's and
shortest paths among the towns in the eurodist data:
Athens Barcelona Brussels Calais Cherbourg
Barcelona 1036
Brussels 635 0
Calais 705 13 0
Cherbourg 819 0 0 0
Cologne 448 139 0 0 0
Copenhagen 507 459 525 537 545
Geneva 879 0 0 0 0
Gibralta 1037 0 0 0 2
Hamburg 438 214 0 0 0
Hook of Holland 530 0 0 0 0
Lisbon 1623 1 216 135 0
Lyons 1022 0 0 0 0
Madrid 1036 0 0 0 0
Marseilles 1037 0 1 0 0
Milan 879 41 0 10 92
Munich 445 61 0 26 0
Paris 798 0 0 0 0
Rome 0 0 0 9 91
Stockholm 508 459 525 537 546
Vienna 0 70 32 35 0
Cologne Copenhagen Geneva Gibralta Hamburg
Barcelona
Brussels
Calais
Cherbourg
Cologne
Copenhagen 222
Geneva 790 300
Gibralta 0 499 0
Hamburg 0 0 0 49
Hook of Holland 0 0 46 0 0
Lisbon 398 662 600 0 334
Lyons 0 327 0 0 0
Madrid 26 499 0 0 48
Marseilles 1 327 0 0 0
Milan 0 171 0 40 102
Munich 0 0 0 89 0
Paris 0 450 0 0 0
Rome 0 98 81 0 29
Stockholm 215 0 300 539 0
Vienna 0 0 0 70 0
Hook of Holland Lisbon Lyons Madrid Marseilles
Barcelona
Brussels
Calais
Cherbourg
Cologne
Copenhagen
Geneva
Gibralta
Hamburg
Hook of Holland
Lisbon 240
Lyons 1 0
Madrid 0 0 0
Marseilles 1 264 0 0
Milan 1 744 0 115 0
Munich 0 670 65 70 160
Paris 0 150 0 0 1
Rome 0 608 134 1 0
Stockholm 581 272 327 539 327
Vienna 0 672 70 41 0
Milan Munich Paris Rome Stockholm
Barcelona
Brussels
Calais
Cherbourg
Cologne
Copenhagen
Geneva
Gibralta
Hamburg
Hook of Holland
Lisbon
Lyons
Madrid
Marseilles
Milan
Munich 0
Paris 57 0
Rome 0 29 91
Stockholm 171 0 451 105
Vienna 139 0 0 0 1
It seems that "marginal" towns (Athens, Lisbon, Stockholm, Copenhagen)
have largest discrepancies.
It also seems that the names are not 'localized', but weird English
forms are used for places like København and Wien so dear to the R core
developers.
cheers, jari oksanen
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