Rhelp wanted

2010-Jan-26 18:15 UTC

### [R] sp package coordinates and gridded problems with as.list()

Dear All I hope that someone can help. I am working with sp pakage and akima library("akima") library(sp) imagine lots of different dataframes, of row = 100 columns = 3 of x and y coordinates with z values I will call these data frames for the sake of this example akima akima<-as.list(1:100) producing 100 dataframes dataframes of the form akima[[i]] I then wish to interp this list of coordinates: akima.li<-as.list(1:100) for (i in 1:100) akima.li[[i]]<-interp(akima[[i]]$x, akima[[i]]$y, akima [[i]]$z) so now I have 100 akima.li which I then transform into a dataframe of the akima.li values y<-as.list(1:100) x<-as.list(1:100) z<-as.list(1:100) for (i in 1:endofrun){ y[[i]]= rep(akima.li[[i]]$x, each = length(akima.li[[i]]$y)) x[[i]] = rep(akima.li[[i]]$y, length(akima.li[[i]]$x)) z[[i]] = as.numeric(akima.li[[i]]$z) } abc<-as.list(1:100) for (i in 1:endofrun){ abc[[i]]<- data.frame(x[[i]], y[[i]], z[[i]]) abc[[i]][is.na(abc[[i]])] <- 0} so now I have 100 dataframes with x and y columns and corresponding z values and any NAs are now 0. This is where my problem starts I wish to use sp to state which columns are coordinates of the form for (i in 1:100) coordinates(abc[[i]])= ~x+y and that all of the dataframes are a grid, such that. for (i in 1:100) gridded(abc[[i]]) = TRUE however I get error messeges such as: Error in function (classes, fdef, mtable) : unable to find an inherited method for function "coordinates<-", for signature "integer" and I do not know what this means. I will then want to then go on to overlay such: datapoint = data.frame(x = 10, y = 20) coordinates(datapoint) = ~x+y gridded(datapoint)=TRUE value<-as.list(1:100) for (i in 1:100) value [[i]]= abc[[i]]@data[overlay(abc[[i]], datapoint),] then I will have a list of 100 "value" for each original dataframe I would be appreciative if someone could tell me how I can allocate coordinate and grided systems to an dataframes which are as.list. I hope that is comprehendable and someone can help. I am very stuck many thanks Sylvestre [[alternative HTML version deleted]]

Paul Hiemstra

2010-Jan-27 10:45 UTC

### [R] sp package coordinates and gridded problems with as.list()

Rhelp wanted wrote:> Dear All I hope that someone can help. > > I am working with sp pakage and akima > library("akima") > library(sp) > > > > imagine lots of different dataframes, of row = 100 columns = 3 of x and y > coordinates with z values I will call these data frames for the sake of this > example akima > > akima<-as.list(1:100) > > producing 100 dataframes dataframes of the form akima[[i]] > > I then wish to interp this list of coordinates: > > akima.li<-as.list(1:100) > for (i in 1:100) akima.li[[i]]<-interp(akima[[i]]$x, akima[[i]]$y, akima > [[i]]$z) > > so now I have 100 akima.li which I then transform into a dataframe of the > akima.li values > > y<-as.list(1:100) > x<-as.list(1:100) > z<-as.list(1:100) > > for (i in 1:endofrun){ > y[[i]]= rep(akima.li[[i]]$x, each = length(akima.li[[i]]$y)) > x[[i]] = rep(akima.li[[i]]$y, length(akima.li[[i]]$x)) > z[[i]] = as.numeric(akima.li[[i]]$z) > } > > abc<-as.list(1:100) > > for (i in 1:endofrun){ > abc[[i]]<- data.frame(x[[i]], y[[i]], z[[i]]) > abc[[i]][is.na(abc[[i]])] <- 0} > > > > so now I have 100 dataframes with x and y columns and corresponding z values > and any NAs are now 0. > > This is where my problem starts I wish to use sp to state which columns are > coordinates of the form > > for (i in 1:100) coordinates(abc[[i]])= ~x+y > > and that all of the dataframes are a grid, such that. > > for (i in 1:100) gridded(abc[[i]]) = TRUE > > however I get error messeges such as: > Error in function (classes, fdef, mtable) : unable to find an inherited > method for function "coordinates<-", for signature "integer" >the input to coordinates should be a data.frame, which abc[[i]] obviously isn't. Look at the meuse dataset from the sp-package for a sample of how such a data.frame should look like. cheers, Paul ps The r-sig-geo mailing list would be a better place to ask this question> and I do not know what this means. > > I will then want to then go on to overlay such: > > datapoint = data.frame(x = 10, y = 20) > coordinates(datapoint) = ~x+y > gridded(datapoint)=TRUE > > value<-as.list(1:100) > > for (i in 1:100) value [[i]]= abc[[i]]@data[overlay(abc[[i]], datapoint),] > > then I will have a list of 100 "value" for each original dataframe > > I would be appreciative if someone could tell me how I can allocate > coordinate and grided systems to an dataframes which are as.list. > > I hope that is comprehendable and someone can help. I am very stuck > > many thanks Sylvestre > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >-- Drs. Paul Hiemstra Department of Physical Geography Faculty of Geosciences University of Utrecht Heidelberglaan 2 P.O. Box 80.115 3508 TC Utrecht Phone: +3130 274 3113 Mon-Tue Phone: +3130 253 5773 Wed-Fri http://intamap.geo.uu.nl/~paul