[R-sig-eco] Warning message when creating ltraj files

[Mathieu Basille]

Dear James,

Sorry for the late answer, I just found that there was no reply to your 
message. For technical questions about adehabitat, you might use 
R-sig-geo instead, or even better, the AniMov mailing list [1].

About your problem: it is actually a simple one, and not directly 
related to adehabitat. You used 'read.delim2' to import the data, which 
is set up with 'dec = ","'. In other words, the point you have in your 
data is not recognized as a decimal separator, and the columns X and Y 
are defined as factors (to check that: 'str(BIRD15)'). Thus, the warning 
messages you got.

The work around is easy: use 'read.delim' instead, which has 'dec = 
"."'. And everything should work smoothly now:

BIRD15 <- read.delim("BIRD15.txt")
BIRD15$Date <- as.POSIXct(BIRD15$Datetime)
BIRD15 <- as.ltraj(BIRD15[, c("X", "Y")], BIRD15$Date, BIRD15$id)

Hope this helps,
Mathieu.


[1] http://lists.faunalia.it/cgi-bin/mailman/listinfo/animov


Le 16/07/2010 12:42, jjw86 a écrit :
>
> Hi
>
> I am currently using adehabitat to run fpt analyses for GPS logger data. I
> can succesfully create ltraj files and most of the subsequent fpt results
> seem normal. However, upon creating the ltraj files i get the following
> warnings:
>
> Warning messages:
> 1: In Ops.factor(x1$x, x2$x) : - not meaningful for factors
> 2: In Ops.factor(x1$y, x2$y) : - not meaningful for factors
> 3: In Ops.factor(x$x, x$x[1]) : - not meaningful for factors
> 4: In Ops.factor(x$y, x$y[1]) : - not meaningful for factors
> 5: In Ops.factor(x1$x, x2$x) : - not meaningful for factors
> 6: In Ops.factor(x1$y, x2$y) : - not meaningful for factors
> 7: In Ops.factor(df[-nrow(df), "x"], df[-1, "x"]) :
>    - not meaningful for factors
> 8: In Ops.factor(df[-nrow(df), "y"], df[-1, "y"]) :
>    - not meaningful for factors
>
> Is this likely to cause inaccuracies and errors within the subsequent fpt
> analyses? I attach example data and R code below. Before analyses i
> interpolated data to 1km intervals as recomended by several papers.
>
> Many Thanks
>
> James Waggitt, University Of Plymouth
>
> Datetime Lon Lat X Y id burst
> 2006-06-17 12:45:09 -5.605818333 51.68021167 759.8326872 5731.347933 2 2
> 2006-06-17 12:46:28 -5.618989125 51.6779461 761.6179035 5731.096681 2 2
> 2006-06-17 12:47:47 -5.632159917 51.67568053 763.4031198 5730.845428 2 2
> 2006-06-17 12:49:06 -5.645330709 51.67341496 765.1883361 5730.594176 2 2
> 2006-06-17 12:50:25 -5.658501501 51.67114939 766.9735524 5730.342924 2 2
> 2006-06-17 12:51:44 -5.671672293 51.66888382 768.7587688 5730.091672 2 2
> 2006-06-17 12:53:03 -5.684843086 51.66661826 770.5439851 5729.84042 2 2
> 2006-06-17 12:54:22 -5.698013878 51.66435269 772.3292014 5729.589168 2 2
> 2006-06-17 12:55:41 -5.71118467 51.66208712 774.1144177 5729.337916 2 2
> 2006-06-17 12:57:00 -5.724355462 51.65982155 775.899634 5729.086664 2 2
> 2006-06-17 12:58:19 -5.737526254 51.65755598 777.6848503 5728.835412 2 2
> 2006-06-17 12:59:37 -5.750697046 51.65529041 779.4700666 5728.58416 2 2
> 2006-06-17 13:00:56 -5.763872707 51.6530372 781.2559429 5728.334278 2 2
> 2006-06-17 13:02:13 -5.777200748 51.65117063 783.0624732 5728.127275 2 2
> 2006-06-17 13:03:30 -5.790330103 51.64890334 784.8420731 5727.875831 2 2
> 2006-06-17 13:04:48 -5.803049452 51.64580912 786.5660992 5727.532681 2 2
> 2006-06-17 13:06:06 -5.815017228 51.64199525 788.1882544 5727.109723 2 2
> 2006-06-17 13:07:25 -5.824768211 51.63605876 789.5099375 5726.451365 2 2
> 2006-06-17 13:08:43 -5.833915635 51.62979132 790.7498121 5725.756304 2 2
> 2006-06-17 13:10:01 -5.842221498 51.6230624 791.8756185 5725.010066 2 2
> 2006-06-17 13:11:20 -5.851542969 51.61700187 793.1390841 5724.337951 2 2
> 2006-06-17 13:12:41 -5.862837645 51.61223993 794.670005 5723.80985 2 2
> 2006-06-17 13:13:58 -5.874783649 51.60827625 796.2892091 5723.370278 2 2
> 2006-06-17 13:15:08 -5.887640557 51.605429 798.0318804 5723.054517 2 2
> 2006-06-17 13:16:18 -5.900478498 51.60255035 799.7719809 5722.735274 2 2
> 2006-06-17 13:17:25 -5.913285934 51.59962122 801.5079466 5722.410433 2 2
> 2006-06-17 13:18:33 -5.925946252 51.59648101 803.2239714 5722.062182 2 2
> 2006-06-17 13:19:44 -5.938163035 51.59270442 804.879878 5721.643358 2 2
> 2006-06-17 13:20:54 -5.950379818 51.58892784 806.5357845 5721.224534 2 2
> 2006-06-17 13:22:12 -5.962496576 51.5850315 808.1781333 5720.792429 2 2
> 2006-06-17 13:25:00 -5.974735183 51.58191516 809.8369978 5720.446827 2 2
> 2006-06-17 13:54:00 -5.97782046 51.5842173 810.2551874 5720.702135 2 2
> 2006-06-17 13:55:50 -5.987469349 51.57828914 811.5630323 5720.0447 2 2
> 2006-06-17 13:57:05 -5.996524082 51.57194876 812.7903433 5719.34155 2 2
> 2006-06-17 13:58:19 -6.005165829 51.56539114 813.9616766 5718.614308 2 2
> 2006-06-17 13:59:34 -6.013324681 51.55863997 815.0675566 5717.865602 2 2
> 2006-06-17 14:00:49 -6.019207639 51.55099247 815.8649537 5717.017493 2 2
> 2006-06-17 14:02:05 -6.024305822 51.54318473 816.5559797 5716.151612 2 2
> 2006-06-17 14:03:25 -6.026860789 51.53485768 816.9022892 5715.22814 2 2
> 2006-06-17 14:19:33 -6.0304573 51.52963023 817.3897731 5714.648415 2 2
> 2006-06-17 14:40:49 -6.037319378 51.52816246 818.3198837 5714.485638 2 2
> 2006-06-17 14:42:10 -6.049596171 51.52448468 819.9839242 5714.077772 2 2
> 2006-06-17 14:43:34 -6.061504423 51.52037391 821.5980113 5713.621887 2 2
> 2006-06-17 14:44:58 -6.073697298 51.51683258 823.2506773 5713.229153 2 2
> 2006-06-17 14:46:22 -6.087168463 51.51557162 825.0766072 5713.089311 2 2
> 2006-06-17 14:47:46 -6.100469176 51.51378646 826.8794334 5712.891337 2 2
> 2006-06-17 14:49:10 -6.113671455 51.5116986 828.6689175 5712.659792 2 2
> 2006-06-17 14:50:35 -6.127016928 51.51000573 830.4778108 5712.472053 2 2
> 2006-06-17 14:52:00 -6.140371319 51.50833761 832.2879127 5712.287059 2 2
> 2006-06-17 14:53:24 -6.15372182 51.50665911 834.0974874 5712.100913 2 2
> 2006-06-17 14:54:45 -6.167266461 51.50645949 835.9333765 5712.078775 2 2
> 2006-06-17 14:56:06 -6.180819904 51.50699426 837.7704588 5712.13808 2 2
> 2006-06-17 14:57:24 -6.193930784 51.50929143 839.5475543 5712.392837 2 2
> 2006-06-17 14:58:41 -6.205605825 51.51313912 841.1300312 5712.819547 2 2
> 2006-06-17 14:59:54 -6.215369025 51.51905136 842.4533703 5713.475216 2 2
> 2006-06-17 15:02:38 -6.225220577 51.52490323 843.788685 5714.124189 2 2
> 2006-06-17 15:31:15 -6.235000221 51.52601035 845.1142529 5714.246969 2 2
> 2006-06-17 15:32:53 -6.24862397 51.52587936 846.9608647 5714.232442 2 2
> 2006-06-17 15:34:17 -6.262220048 51.52563384 848.8037257 5714.205215 2 2
> 2006-06-17 15:35:39 -6.275513136 51.52377376 850.6055184 5713.998931 2 2
> 2006-06-17 15:37:03 -6.288852137 51.52205889 852.4135344 5713.808752 2 2
> 2006-06-17 15:38:30 -6.30228122 51.52062892 854.2337603 5713.650168 2 2
> 2006-06-17 15:39:55 -6.314823289 51.51742535 855.9337574 5713.294891 2 2
> 2006-06-17 15:41:19 -6.327056235 51.51371361 857.5918546 5712.883258 2 2
> 2006-06-17 15:42:42 -6.338679969 51.50929423 859.1673771 5712.393148 2 2
> 2006-06-17 15:44:04 -6.350015708 51.50460799 860.7038638 5711.873442 2 2
> 2006-06-17 15:45:26 -6.361006276 51.49960189 862.1935648 5711.318265 2 2
> 2006-06-17 15:46:50 -6.372390229 51.49495452 863.7365864 5710.80287 2 2
> 2006-06-17 15:48:15 -6.383691084 51.49025905 865.2683449 5710.282141 2 2
> 2006-06-17 15:49:37 -6.392899787 51.48401556 866.5165255 5709.589737 2 2
> 2006-06-17 15:51:02 -6.401744204 51.47760264 867.7153294 5708.878543 2 2
> 2006-06-17 15:52:47 -6.408750989 51.47033503 868.6650541 5708.072563 2 2
> 2006-06-17 16:02:35 -6.412186884 51.46420518 869.1307676 5707.392761 2 2
> 2006-06-17 16:03:55 -6.41811763 51.45657555 869.9346421 5706.546633 2 2
> 2006-06-17 16:05:13 -6.425035311 51.44928723 870.8722894 5705.738357 2 2
> 2006-06-17 16:06:29 -6.432273549 51.44210976 871.8533861 5704.942374 2 2
> 2006-06-17 16:07:51 -6.437726694 51.43434393 872.5925249 5704.081141 2 2
> 2006-06-17 16:09:15 -6.443531365 51.42668964 873.3793108 5703.232279 2 2
> 2006-06-17 16:10:44 -6.450381662 51.41936717 874.3078246 5702.420215 2 2
> 2006-06-17 16:12:10 -6.461181677 51.414741 875.7716973 5701.907172 2 2
> 2006-06-17 16:13:35 -6.473299993 51.41103917 877.4142572 5701.496638 2 2
> 2006-06-17 16:14:51 -6.477585584 51.40299442 877.9951416 5700.604473 2 2
> 2006-06-17 16:16:07 -6.481071467 51.39483947 878.4676306 5699.700087 2 2
> 2006-06-17 16:17:20 -6.482617855 51.38641723 878.6772336 5698.766059 2 2
> 2006-06-17 16:18:34 -6.48434955 51.37801137 878.9119537 5697.833847 2 2
> 2006-06-17 16:19:46 -6.486604809 51.36965176 879.2176396 5696.906764 2 2
> 2006-06-17 16:21:00 -6.489352436 51.36137731 879.5900628 5695.989126 2 2
> 2006-06-17 16:22:19 -6.494304617 51.35348418 880.2612992 5695.113775 2 2
> 2006-06-17 16:23:37 -6.500079354 51.34583148 881.0440277 5694.265089 2 2
> 2006-06-17 16:24:52 -6.506600177 51.33839687 881.9278833 5693.44059 2 2
> 2006-06-17 16:28:24 -6.51333753 51.33104056 882.8410884 5692.624773 2 2
> 2006-06-17 17:06:27 -6.515562808 51.32398299 883.1427104 5691.842087 2 2
> 2006-06-17 18:11:25 -6.51044265 51.31646789 882.4487059 5691.00866 2 2
> 2006-06-17 18:30:49 -6.513971397 51.3096061 882.9270049 5690.247686 2 2
> 2006-06-17 18:33:24 -6.525496614 51.30574406 884.4891741 5689.819385 2 2
> 2006-06-17 18:35:11 -6.537297299 51.30178094 886.0886812 5689.379874 2 2
> 2006-06-17 18:36:55 -6.548234383 51.2967711 887.5711327 5688.824282 2 2
> 2006-06-17 18:39:04 -6.55943764 51.29199975 889.0896623 5688.295138 2 2
> 2006-06-17 18:41:01 -6.571151704 51.28773377 890.6774284 5687.82204 2 2
> 2006-06-17 18:42:50 -6.581258562 51.28210507 892.0473481 5687.197815 2 2
> 2006-06-17 18:44:34 -6.591948436 51.27693565 893.4962919 5686.624525 2 2
> 2006-06-17 18:46:16 -6.603029955 51.27207904 894.9983208 5686.085926 2 2
> 2006-06-17 18:48:09 -6.613023239 51.2663544 896.3528462 5685.451062 2 2
> 2006-06-17 18:50:06 -6.62345911 51.26095886 897.7673616 5684.852695 2 2
> 2006-06-17 18:52:03 -6.634632184 51.25721065 899.2817999 5684.437018 2 2
> 2006-06-17 18:53:57 -6.647732064 51.25936867 901.0574046 5684.676343 2 2
> 2006-06-17 18:56:02 -6.661190369 51.25899662 902.8815914 5684.635082 2 2
> 2006-06-17 18:57:36 -6.66997131 51.25325582 904.0717917 5683.998426 2 2
> 2006-06-17 18:59:00 -6.677554087 51.24623155 905.0995884 5683.219433 2 2
> 2006-06-17 19:10:35 -6.67831668 51.24119225 905.202953 5682.660574 2 2
> 2006-06-17 19:42:47 -6.665180297 51.24042546 903.4224006 5682.575537 2 2
> 2006-06-17 19:53:31 -6.661310929 51.23369982 902.8979326 5681.829661 2 2
> 2006-06-17 19:54:39 -6.659322935 51.22531439 902.6284728 5680.899715 2 2
> 2006-06-17 19:55:51 -6.658278764 51.21704619 902.4869421 5679.98277 2 2
> 2006-06-17 19:57:34 -6.665223113 51.20977016 903.428204 5679.175856 2 2
> 2006-06-17 20:03:37 -6.673989384 51.20445515 904.6164158 5678.58642 2 2
> 2006-06-17 20:33:50 -6.660543831 51.20454307 902.7939574 5678.596171 2 2
> 2006-06-17 20:58:24 -6.652478201 51.20259139 901.700713 5678.379729 2 2
> 2006-06-17 21:00:23 -6.662351971 51.19679594 903.0390391 5677.737012 2 2
> 2006-06-18 04:10:00 -6.648764576 51.19798009 901.197355 5677.868335 2 2
> 2006-06-18 05:39:21 -6.646279915 51.19313102 900.8605752 5677.330571 2 2
> 2006-06-18 05:41:36 -6.636382678 51.19693402 899.5190681 5677.752325 2 2
> 2006-06-18 05:42:20 -6.627647362 51.20340794 898.3350522 5678.470284 2 2
> 2006-06-18 05:43:05 -6.618912046 51.20988186 897.1510362 5679.188243 2 2
> 2006-06-18 05:43:49 -6.61017673 51.21635578 895.9670202 5679.906203 2 2
> 2006-06-18 05:44:36 -6.598174493 51.2198331 894.340194 5680.291838 2 2
> 2006-06-18 05:45:24 -6.585362526 51.22256769 892.6036142 5680.595106 2 2
> 2006-06-18 05:46:11 -6.572550559 51.22530229 890.8670343 5680.898373 2 2
> 2006-06-18 05:46:57 -6.561748505 51.22989764 889.4028852 5681.407998 2 2
> 2006-06-18 05:47:40 -6.552933223 51.23633232 888.2080303 5682.121606 2 2
> 2006-06-18 05:48:24 -6.544117941 51.242767 887.0131755 5682.835213 2 2
> 2006-06-18 05:49:07 -6.535302659 51.24920168 885.8183206 5683.548821 2 2
> 2006-06-18 05:49:52 -6.525288867 51.25488895 884.4610153 5684.179541 2 2
> 2006-06-18 05:50:38 -6.515010116 51.260411 883.0677966 5684.791938 2 2
> 2006-06-18 05:51:23 -6.504731365 51.26593305 881.6745779 5685.404334 2 2
> 2006-06-18 05:52:08 -6.494452614 51.27145509 880.2813592 5686.01673 2 2
> 2006-06-18 05:52:51 -6.484575415 51.27725729 878.9425682 5686.660195 2 2
> 2006-06-18 05:53:34 -6.4747684 51.28310845 877.6132904 5687.30909 2 2
> 2006-06-18 05:54:17 -6.464961386 51.28895961 876.2840126 5687.957985 2 2
> 2006-06-18 05:55:00 -6.455824298 51.29521408 875.0455389 5688.651608 2 2
> 2006-06-18 05:55:43 -6.446893401 51.30159269 873.8350131 5689.358997 2 2
> 2006-06-18 05:56:25 -6.437962504 51.30797129 872.6244874 5690.066385 2 2
> 2006-06-18 05:57:11 -6.427924521 51.31284213 871.2639032 5690.606562 2 2
> 2006-06-18 05:58:04 -6.41436271 51.31291377 869.4256868 5690.614507 2 2
> 2006-06-18 05:58:57 -6.400800899 51.31298541 867.5874704 5690.622453 2 2
> 2006-06-18 06:24:12 -6.394060931 51.3097024 866.6739111 5690.258365 2 2
> 2006-06-18 06:26:12 -6.381236635 51.31241201 864.9356601 5690.558862 2 2
> 2006-06-18 06:27:29 -6.368058522 51.31429179 863.1494514 5690.76733 2 2
> 2006-06-18 06:28:21 -6.354664144 51.31562541 861.3339295 5690.915229 2 2
> 2006-06-18 06:29:12 -6.341269766 51.31695903 859.5184076 5691.063127 2 2
> 2006-06-18 06:30:03 -6.327875389 51.31829264 857.7028857 5691.211025 2 2
> 2006-06-18 06:30:53 -6.31623472 51.32194416 856.1250678 5691.615979 2 2
> 2006-06-18 06:31:42 -6.306090487 51.32757353 854.7500822 5692.240278 2 2
> 2006-06-18 06:32:30 -6.295946255 51.3332029 853.3750965 5692.864577 2 2
> 2006-06-18 06:33:19 -6.285802022 51.33883228 852.0001109 5693.488876 2 2
> 2006-06-18 06:34:06 -6.275126353 51.34403281 850.5530925 5694.065616 2 2
> 2006-06-18 06:34:50 -6.263830738 51.34873308 849.0220444 5694.586877 2 2
> 2006-06-18 06:35:35 -6.252535124 51.35343335 847.4909964 5695.108139 2 2
> 2006-06-18 06:36:21 -6.241331129 51.35821876 845.9723669 5695.638842 2 2
> 2006-06-18 06:37:08 -6.23022774 51.36309766 844.4673738 5696.179913 2 2
> 2006-06-18 06:37:56 -6.219124351 51.36797656 842.9623806 5696.720984 2 2
> 2006-06-18 06:38:43 -6.208240303 51.37302629 841.4871178 5697.281 2 2
> 2006-06-18 06:39:29 -6.198237737 51.37876253 840.1313342 5697.917151 2 2
> 2006-06-18 06:40:14 -6.188235171 51.38449877 838.7755506 5698.553301 2 2
> 2006-06-18 06:41:00 -6.178232605 51.39023501 837.4197671 5699.189452 2 2
> 2006-06-18 06:41:45 -6.16823004 51.39597125 836.0639835 5699.825602 2 2
> 2006-06-18 06:42:31 -6.158227474 51.40170749 834.7081999 5700.461753 2 2
> 2006-06-18 06:44:25 -6.148065919 51.4073197 833.3308664 5701.084148 2 2
> 2006-06-18 06:46:58 -6.135207303 51.40566927 831.5879635 5700.901115 2 2
> 2006-06-18 06:48:24 -6.12195644 51.40407371 829.7918941 5700.724167 2 2
> 2006-06-18 06:49:19 -6.108379272 51.40371672 827.9515962 5700.684577 2 2
> 2006-06-18 06:50:13 -6.094802105 51.40335974 826.1112983 5700.644987 2 2
> 2006-06-18 06:51:01 -6.081687667 51.40553402 824.3337205 5700.886116 2 2
> 2006-06-18 06:51:48 -6.068588501 51.40779184 822.5582126 5701.136509 2 2
> 2006-06-18 06:52:36 -6.05543081 51.40987175 820.774772 5701.367171 2 2
> 2006-06-18 06:53:30 -6.041960812 51.41100227 818.9490003 5701.492545 2 2
> 2006-06-18 06:54:23 -6.028490814 51.41213278 817.1232286 5701.61792 2 2
> 2006-06-18 06:55:17 -6.014938291 51.41254 815.2862711 5701.663081 2 2
> 2006-06-18 06:56:12 -6.001346861 51.41260622 813.4440399 5701.670425 2 2
> 2006-06-18 06:57:07 -5.98775543 51.41267244 811.6018087 5701.677768 2 2
> 2006-06-18 06:58:02 -5.974175598 51.41253374 809.7611497 5701.662386 2 2
> 2006-06-18 06:58:54 -5.960625316 51.41187295 807.9244959 5701.589104 2 2
> 2006-06-18 06:59:47 -5.947075033 51.41121216 806.0878421 5701.515822 2 2
> 2006-06-18 07:00:41 -5.933506128 51.41073386 804.2486641 5701.462779 2 2
> 2006-06-18 07:01:34 -5.919932857 51.41029834 802.4088944 5701.41448 2 2
> 2006-06-18 07:02:28 -5.906357595 51.40991035 800.5688548 5701.371451 2 2
> 2006-06-18 07:03:20 -5.892766569 51.40989859 798.7266784 5701.370148 2 2
> 2006-06-18 07:04:11 -5.879175543 51.40988684 796.8845021 5701.368844 2 2
> 2006-06-18 07:05:01 -5.865685103 51.41065218 795.0559596 5701.453721 2 2
> 2006-06-18 07:05:50 -5.852273708 51.41202819 793.2381311 5701.60632 2 2
> 2006-06-18 07:06:39 -5.838862313 51.4134042 791.4203026 5701.75892 2 2
> 2006-06-18 07:07:29 -5.825418459 51.41464934 789.5980745 5701.897006 2 2
> 2006-06-18 07:08:19 -5.811954736 51.41581437 787.7731533 5702.026209 2 2
> 2006-06-18 07:09:09 -5.798491013 51.4169794 785.9482321 5702.155411 2 2
> 2006-06-18 07:09:54 -5.787447046 51.42188136 784.4512933 5702.699039 2 2
> 2006-06-18 07:10:39 -5.7764647 51.42687848 782.9627067 5703.253221 2 2
> 2006-06-18 07:11:25 -5.765482353 51.4318756 781.4741202 5703.807403 2 2
> 2006-06-18 07:12:10 -5.756485544 51.43816682 780.2546604 5704.505101 2 2
> 2006-06-18 07:12:56 -5.748003871 51.4447938 779.105024 5705.240034 2 2
> 2006-06-18 07:13:42 -5.739522198 51.45142078 777.9553877 5705.974968 2 2
> 2006-06-18 07:14:35 -5.72728434 51.45491467 776.2966247 5706.362441 2 2
> 2006-06-18 07:15:29 -5.714676499 51.45809995 774.5877127 5706.71569 2 2
> 2006-06-18 07:30:48 -5.703759612 51.4568175 773.1079988 5706.573466 2 2
> 2006-06-18 07:32:39 -5.696167729 51.46360426 772.0789677 5707.326119 2 2
> 2006-06-18 07:33:51 -5.688566796 51.47063575 771.0487101 5708.105913 2 2
> 2006-06-18 07:34:44 -5.681469717 51.47786456 770.0867466 5708.90759 2 2
> 2006-06-18 07:35:28 -5.674640269 51.48519818 769.1610588 5709.72089 2 2
> 2006-06-18 07:36:12 -5.667810822 51.49253181 768.235371 5710.534191 2 2
> 2006-06-18 07:36:55 -5.660981374 51.49986543 767.3096833 5711.347492 2 2
> 2006-06-18 07:37:39 -5.653269016 51.50673633 766.2643226 5712.109476 2 2
> 2006-06-18 07:38:23 -5.64281024 51.51216784 764.8467027 5712.711831 2 2
> 2006-06-18 07:39:08 -5.632351465 51.51759934 763.4290828 5713.314187 2 2
> 2006-06-18 07:39:52 -5.622135669 51.52318135 762.0443973 5713.933233 2 2
> 2006-06-18 07:40:36 -5.61348266 51.52973133 760.8715376 5714.659627 2 2
> 2006-06-18 07:41:21 -5.604829652 51.53628131 759.6986778 5715.386021 2 2
> 2006-06-18 07:42:05 -5.596176643 51.54283129 758.525818 5716.112415 2 2
> 2006-06-18 07:42:49 -5.587523635 51.54938126 757.3529583 5716.838809 2 2
> 2006-06-18 07:43:33 -5.578870626 51.55593124 756.1800985 5717.565203 2 2
> 2006-06-18 07:44:19 -5.571172583 51.56284924 755.1366781 5718.332412 2 2
> 2006-06-18 07:45:08 -5.565611693 51.57059086 754.3829352 5719.190959 2 2
> 2006-06-18 07:45:56 -5.560050802 51.57833248 753.6291922 5720.049506 2 2
> 2006-06-18 07:46:45 -5.554489912 51.5860741 752.8754493 5720.908053 2 2
> 2006-06-18 07:47:34 -5.548929022 51.59381571 752.1217063 5721.766601 2 2
> 2006-06-18 07:48:23 -5.543368132 51.60155733 751.3679634 5722.625148 2 2
> 2006-06-18 07:49:11 -5.537807242 51.60929895 750.6142204 5723.483695 2 2
> 2006-06-18 07:50:00 -5.532246352 51.61704057 749.8604775 5724.342242 2 2
> 2006-06-18 07:50:49 -5.526685462 51.62478218 749.1067345 5725.20079 2 2
> 2006-06-18 07:51:37 -5.521124572 51.6325238 748.3529915 5726.059337 2 2
> 2006-06-18 08:06:02 -5.508869792 51.63209301 746.6919348 5726.011562 2 2
> 2006-06-18 08:08:30 -5.50812194 51.63989581 746.5905683 5726.876894 2 2
>
> BIRD15=read.delim2("BIRD15.txt")
>> date=as.POSIXct(BIRD15[,1])
>> id=as.factor(BIRD15[,6])
>> burst=as.factor(BIRD15[,7])
>> xy=data.frame(BIRD15[,4],BIRD15[,5])
>> BIRD15=as.ltraj(xy, date, id, burst = id, typeII = TRUE,slsp = c("remove",
>> "missing"))
>

-- 

~$ whoami
Mathieu Basille, Post-Doc

~$ locate
Laboratoire d'Écologie Comportementale et de Conservation de la Faune
+ Centre d'Étude de la Forêt
Département de Biologie
Université Laval, Québec

~$ info
http://ase-research.org/basille

~$ fortune
``If you can't win by reason, go for volume.''
Calvin, by Bill Watterson.