Dear list, I am a new R user and wonder if somebody could help with this problem:
The entries in column "currentcentroid" in data frame "fish" change in relation to the entry in column "angles" (example is given below). "currentcentroid" is a gridpoint. After updating it according to "angles" I would like to also update the corresponding UTM coordinates "currentUTMX" and "currentUTMY" from data frame "WaterCentroids", which stores centroids and their corresponding UTM coordinates. I would like to write an if statement that relates "currentcentroid" and "CurrentUTMX" and "CurrentUTMY" in dataframe "fish" to "centroid" and "UTMX" and "UTMY" in dataframe "WaterCentroids".But I am having a hrad time figuring it out. Is there anybody who could help or give me a hint ? The purpose is to simulate the path of fish on a grid. Many thanks.. Juliane This is my dataframe so far: nfish=10 startpoints=sample(282816,nfish) anglesfromnorth=c(0,45,90,135,180,225,270,360) anglenumber=sample(1:8,size=nfish,replace=TRUE) angles=anglesfromnorth[anglenumber] fish=data.frame(WaterCentroids[startpoints, 3:5],angles=angles,currentcentroid=0,currentUTMX=0, currentUTMY=0) if (fish$angles==45){fish$currentcentroid=fish$centroid +1} else {fish$currentcentroid=fish$centroid} How do I update "currentUTMX" and "currentUTMY" from df[WaterCentroids] now ? __________________________________________________________ Not happy with your email address?. Get the one you really want - millions of new email addresses available now at Yahoo! http://uk.docs.yahoo.com/ymail/new.html _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo