"test.data" <-
structure(list(x = structure(c(10.2420950223404, 3.80376523711237, 
9.10894898014071, 9.62401536295848, -2.42853799498812, -12.626852374789, 
-0.419779101996896, -7.88824165286121, 3.54623204570348, -16.9019033521803, 
-27.2032310085453, -6.18852258956094, -5.26140310048807, -12.2147992685346, 
-25.5550185835271, -15.6657440334172, 21.109995699806, 12.9204402129956, 
33.8836419936979, 28.1148985061338, 10.2420950223404, 3.80376523711237, 
9.10894898014071, 9.62401536295848, -2.42853799498812, -12.626852374789, 
-0.419779101996896, -7.88824165286121, 3.54623204570348, -16.9019033521803, 
-8.81404505952784, 6.475624941694, -12.2040623901154, -18.5689928883614, 
6.8907291046231, -14.9714234763093, -2.03401039835273, 10.6958505981398, 
12.287083222701, -4.939739538856, 11.4568748968428, 20.2432463455088, 
35.0486281566463, 28.0610414140067, 23.2873435403219, -20.2294095400778, 
-19.6759373228389, -16.9777602637997, -17.5312324810386, -18.4998088612067, 
-8.81404505952784, 6.475624941694, -12.2040623901154, -18.5689928883614, 
6.8907291046231, -14.9714234763093, -2.03401039835273, 10.6958505981398, 
12.287083222701, -4.939739538856), .Dim = c(30, 2), .Dimnames = list(
    c("170310032", "170310037", "170310050", "170311002", "170311003", 
    "170311601", "170314002", "170314003", "170317002", "170436001", 
    "170890005", "170970001", "170971002", "170973001", "171110001", 
    "171971008", "180891016", "180892008", "181270020", "181270024", 
    "170310032", "170310037", "170310050", "170311002", "170311003", 
    "170311601", "170314002", "170314003", "170317002", "170436001"
    ), c("East.West", "North.South"))), y = c(36.4902936963152, 
34.6396930821552, 31.6444005657229, 34.4646956838262, 37.7204739668803, 
40.1342965426748, 37.0181086910068, 38.4001686365134, 44.0485589002946, 
38.4870329290307, 42.2402282830657, 40.0049235817847, 42.1090485712195, 
39.6319596353327, 42.8054712629932, 44.1097465187358, 35.1186331327201, 
46.898470931915, 42.9564231070325, 46.6868555984414, 36.4902936963152, 
34.6396930821552, 31.6444005657229, 34.4646956838262, 37.7204739668803, 
40.1342965426748, 37.0181086910068, 38.4001686365134, 44.0485589002946, 
38.4870329290307), knots.data = c(10.6958505981398, 12.287083222701, 
11.4568748968428, -17.5312324810386, -15.6657440334172, 28.1148985061338, 
35.0486281566463, -5.26140310048807, -12.2040623901154, 23.2873435403219
)), .Names = c("x", "y", "knots.data"))