[josm-dev] LatLon.greatCircleDistance Bug?

[Detlef Reichl]

Am Montag, den 19.01.2009, 17:15 +0100 schrieb Tobias Wendorff:
Hi Tobias,

> The bug must be in the other parts.

I'm a little step further. Form the MapScaller class i printed out the
ll1, ll2 and dist value to the console. It looks like this:

ll1 64.5635383519239 : -19.701032734051942
ll2 64.5635383519239 : -9.890120706057816
dist 468619.7921204448

ll1 65.91688367961092 : -22.856876103056717
ll2 65.91688367961092 : -11.955862738618798
dist 494557.8424123941

ll1 67.34105605688401 : -26.363368735284247
ll2 67.34105605688401 : -14.251131663686559
dist 518612.50496088184

ll1 68.82977522568474 : -30.259471659981504
ll2 68.82977522568474 : -16.801430469317406
dist 539957.2886111567

ll1 70.3743573179418 : -34.58847490964512
ll2 70.3743573179418 : -19.635095808907234
dist 557687.3702770402

ll1 71.963536631957 : -39.398478520382476
ll2 71.963536631957 : -22.783612852895935
dist 570850.2680160615

ll1 73.58339022047235 : -44.74292697675731
ll2 73.58339022047235 : -26.281965123994485
dist 578490.4937988957

ll1 75.21740411282117 : -50.681203039396024
ll2 75.21740411282117 : -30.169023202992882
dist 579708.5723878946

ll1 76.84671859283488 : -57.27928755343901
ll2 76.84671859283488 : -34.487976624102195
dist 573732.9917813947

ll1 78.45058287944866 : -64.61049256904235
ll2 78.45058287944866 : -39.28681375866812
dist 560001.2842969369

ll1 80.00703564250523 : -72.75627591971273
ll2 80.00703564250523 : -44.61885501929692
dist 538243.7455625333

ll1 81.49380667414835 : -81.80714630934649
ll2 81.49380667414835 : -50.54334530888447
dist 508560.6560124746

ll1 82.88940754706157 : -91.86366896449512
ll2 82.88940754706157 : -57.12611229731509
dist 471481.77217010665

ll1 84.17434746547553 : -103.03758302577135
ll2 84.17434746547553 : -64.44029784001577
dist 427995.86036005936


Up to a longitude difference of aprox 20 degrees it looks fine.

The strange thing is, I copied the calculation to a small test program
and feed it with similar data and that worked like expected :-/

I think that needs an expert ;-)

>  Sorry, I just started with JOSM ...
Me too (on the code side).

> Tried to open a TRAC?
I don't like to open a bug with "there is a bug, but i don't know
where..."

Cheers, detlef