Thank you very much for this quick reply Dr. Bivand. I am taking good notes of your suggestions.
I'm a little concern about your comments that my data are not a marked point process and would like to verify with you a few points. You are correct that my points - the catch positions are essentially fishermen decisions. However, I am using at-sea observer data, which are (technically) random sampling of a subset of all fishing effort (usually between 5-15 percent/year, although it varies between years, fisheries, and regions). As a starting point, I would like to reproduce what Gardner et al. (2008) have done. [Gardner B, Sullivan PJ, Morreale SJ, Epperly SP. Spatial and temporal statistical analysis of bycatch data: patterns of sea turtle bycatch in the North Atlantic. Canadian Journal of Fisheries and Aquatic Sciences. 2008;65(11):2461-2470. Available from: http://www.nrcresearchpress.com/doi/abs/10.1139/F08-152]. However, my data are somewhat more complex since I am dealing with different fishing gears (over 15 types) over the spend of 15 years (1995-2010). I would like to go beyond describing the space-time clustering of catch events and try to model these events to oceanographical variables, such as temperature and ocean-color derived chlorophyll concentration. I would be grateful for any of your thoughts, comments, and/or suggestions. Thank you very much for your time, Best, ~~Aurelie ----- Aurelie Cosandey-Godin Ph.D. Candidate, Department of Biology Industrial Graduate Fellow, WWF-Canada Dalhousie University | Biology Dept. |Halifax, NS, Canada Email: god...@dal.ca | Web: wormlab.biology.dal.ca -------------------------------------------------------------------------- Want to learn more about sharks in Atlantic Canada? Visit ShARCC! www.atlanticsharks.org -- View this message in context: http://r-sig-geo.2731867.n2.nabble.com/Converting-spatialPointsDataFrame-into-ppp-tp2764866p6804881.html Sent from the R-sig-geo mailing list archive at Nabble.com. _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo