search for: leaflovesun

Dear all, I wanna to do multiple comparison test for proportions (multiple chi squre ?), could someone tell me how in R, thank you!

Dear listers, A quick question about breaks in hist(). The histogram is highly screwed to the right, say, the range of the vector is [0, 2], but 95% of the value is squeezed in the interval (0.01, 0.2). My question is : how to set the breaks then make the histogram look even? Thanks in advance, Leaf

Dear all, I have a date frame like this: X Y Z 22 24 4.3 2.3 3.4 5.3 ..... .... 57.2 23.4 34 What my purpose is: to sort the data frame by either X, Y or Z. sample output is (sorted by X) : X Y Z 2.3 3.4 5.3 ..... ...... 22 24 4.3 ... 57.2 23.4 34 I have no idea how to use sort, order or rank functions. Please help me out. Thanks! Leaf

Dear all, Is there any simple way in R that can I put the all the interactions of the variables in the OLS model? e.g. I have a bunch of variables, x1,x2,.... x20... I expect then to have interaction (e.g. x1*x2, x3*x4*x5... ) with some combinations(2 way or higher dimensions). Is there any way that I can write the model simpler? Thanks! Leaf

Dear all, I got point data of trees. I was wondering if anybody has experience in searching the neighbors within a specified distance efficiently. X Y Z 99 34 65 98 35 29 98 34 28 99 33 33 98 32 23 99 33 21 99 33 22 99 32 24 99 30 23 ... What I want to do is : searching for the neighbors with a distance R for each tree & the neighbor must have a bigger Z.

Hi all, I need to write and read a list in R. I did r.site.search, found there is a package "rmutil" doing this, unfortunately it is not on the list of package. In another words, I can't install it from any CRAN mirror. Anybody has idea about this? or any suggestion about the list? Thanks! Best! Leaf

Hi all, Has anybody have the experience in the errors: Error in data.frame(..., check.names=FALSE): arguments imply differing number of rows: 343,15 This is the error occured in the middle of the program. I don't think the data frame has any problem, if there is problem with the program, why it happened in the middle? Does anybody have such an experience? It seems so weird to me. Thanks a

Dear All, Is there anybody has the experience in using variogram(gstat) ? Please kindly give me some hints about the results. I used variogram() to build a semivariogram plot as: tr.var=variogram(Incr~1,loc=~X+Y,data=TRI2TU,width=5) then fir the variogram to get the parameters as: v.fit = fit.variogram(tr.var,vgm(0.5,"Exp",300,1)) v.fit model psill range 1 Nug 1.484879

Dear all, I'd like to change a point pattern to a grid of cells and use one of the variables as the output. e.g. The point pattern is of a window of (500*500) and several features such as pH, SoilType etc. I like to divide it into a grid with cell size 5*5, and use the mean of the point values falling inside the cell as the output. Is there any package in R working with this? Thanks in