Creating SpatialGridDataFrame - unequal number of objects
Re: [R-sig-Geo] R spatial matrix to SpatialGridDataFrameEdzer Pebesma Tue, 26 Jan 2010 00:54:21 -0800?suggested the following to?Ian McCallum - herein adapted ?bike_1<- list(x = 1:1824, y = 1:1824, z = matrix(rep(1824:1, each=1824), ncol=1824, byrow=TRUE))
bgrid<- GridTopology(cellcentre.offset = c(bike_1$x[1], bike_1$y[1]), cellsize =?+ c(bike_1$x[1], bike_1$y[1]), cells.dim = dim(bike_1$z)) bike_1_sgdf<- SpatialGridDataFrame(bgrid, data.frame(depth =?+ as.vector(bike_1$z[,ncol(bike_1$z):1]))) image(bike_1_sgdf, axes = TRUE)
This produces the highly desired and previously elusive SGDF. I would neverhave figured out the "data.frame(depth = & etc" myself and have plenty of examples ofSGDF's that contain none of the values I sought to show for my efforts. This approach requires x=z and so my prior z=y is untenable. When viewed in imagethe values seem rotated clockwise 90 deg, which I guess is just matrix vs raster origin.? I was hoping to?attain a grid of x= 1824, y= 1368, and z values descending?from 1368:1 by column. ?And thence create a Terragen file through rgdal. I suppose I can rotate, clip & etc post rgdal but wonder if I can simplify my approach. Thanks,Chris ----------------------------------------
From: tgriffin at uaex.edu Subject: RE: [R-sig-Geo] Creating SpatialGridDataFrame - unequal number of objects Date: Sat, 28 May 2011 18:39:09 -0500 To: sglish at hotmail.com; r-sig-geo at r-project.org Terry Griffin, PhD tgriffin at uaex.edu 501.249.6360 -----Original Message----- From: Chris English Sent: Saturday, May 28, 2011 11:20 AM To: r-sig-geo at r-project.org Subject: [R-sig-Geo] Creating SpatialGridDataFrame - unequal number of objects Dear List: I have a SpatialGrid for which I am trying to make adata.frame and thence a SpatialGridDataFrame. I can't seem to get the size of data.frame and gridto match up. I assume I'm missing something straight forward. summary(grid1)Object of class SpatialGridCoordinates: min maxx 0.5 1824.5y 0.5 1368.5Is projected: NA proj4string : [NA]Number of points: 2Grid attributes: cellcentre.offset cellsize cells.dimx 1 1 1824y 1 1 1368> help(str)> bike_mat<- matrix(rep(1368:1, each=1824), ncol=1824, byrow=TRUE)> bike_df<- as.data.frame(bike_mat)> bike_sgdf_1<- SpatialGridDataFrame(grid1,bike_df)Error in validityMethod(object) : unequal number of objects in full grid and data slot Thank you for you assistance. Chris
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