<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;">Hi everybody,<div id="yiv1031993909"><div><div style="color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); font-family: times new roman,new york,times,serif; font-size: 12pt;"><div>I have a data base (baseat_part.txt) on a plant species with records attached to the centers of grid cells.<br>Because I don't have softwares as arcgis, I'd like to learn spatial analyses with R.<br>I have wgs84 coordinates and 3 status for the species population (casual=50 plants; unknown=500; established=1500).</div>I just tried to see data with a simple plot (scriptat_part.R) but I must represent the density of population. I found kde2d but I don't know if kernel suits and what it
means. <br>The grid resolution can vary (not in this partial base but in others; '1' means 3km and '2' means 6 km so I must assign them to the first ones).<br>I just heard about krigeage and <span class="st">nearest neighbor</span>s but I don't know how to use them to calculate the number of plants by grid cell.<br>The objective is to have 'net cbf' format because I will transfer the distribution map to emission map (with estimated quantities of pollen production).<br>Thanks a lot for your help.<br>Alice<br>------------------------------------------------<br>Alice SCHAFFHAUSER <br>Post-doctoral fellow <br>ATOPICA project<br>Plant and fire ecology (FIRE PARADOX) <br>Paleoecology of peatlands and pedogeomorphology <br>------------------------------------------------ <br>aliceschaffhauser@yahoo.fr <br>alice.schaffhauser@lsce.ipsl.fr <br>------------------------------------------------ <br>Work address: <br>LSCE-CEA Orme des Merisiers, <br>91191
Gif-sur-Yvette cedex <br>France <br>Tel : 33 (0)1 69 08 77 23 <br>Fax : 33 (0)1 69 08 77 16<div>
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