[R] convert to grid file

Petr PIKAL petr.pikal at precheza.cz
Thu Sep 1 17:01:58 CEST 2011


Hi

I do not know sp package therefore I can not help you. Anyway without 
knowing "what is wrong" and without some reproducible example you hardly 
get any reasonable answer.

It seems to me that your d list especially x and y is not what you expect 
to be. 

see

str(d)

430071.4887:460006.8067

will resilt in row of integers from 430071 to 460006. I believe it is not 
what you want.

Regards
Petr


> 
> Thank you
> 
> I want to make a map from my spatial data that I can show it in GIS. 
> I used the package sp and 
> 
> d<- list(x=430071.4887:460006.8067, y =3390040.0591:3420006.2701, z = 
> matrix(mat, 970, 960))
> gt<- GridTopology(cellcentre.offset = c(d$x[1], d$y[1]),
> cellsize=c(diff(d$x[1:2]), diff(d$y[1:2])), cells.dim = dim(d$z))
> grdatts<-SpatialGridDataFrame(gt, data.frame(depth =
> as.vector(d$z[,ncol(d$z):1])))
> image(grd.atts, axes=TRUE)
> grd<-SpatialGridDataFrame(gt, data.frame(depth =
> as.vector(d$z[,ncol(d$z):1])))
> 
> It doesn't work and I think it is wrong. 
> 
> Thanks
> 
> From: Petr PIKAL <petr.pikal at precheza.cz>
> To: azam jaafari <azamjaafari at yahoo.com>
> Cc: R-help <r-help at r-project.org>
> Sent: Thursday, September 1, 2011 10:22 AM
> Subject: Re: [R] convert to grid file
> 
> Hi
> 
> > Thank you Petr
> > 
> > It work. 
> > 
> > Now I have a matrix 970*960. If I want to convert to spatial grid 
(each 
> > pixel has x and y coordinate). 
> > How can I do? 
> 
> I do not understand. What do you want to do with your data? Maybe you 
> could consult spatial package or CRAN Task views. One option could be to 

> make vectors of row and columns coordinates. But it depends on what you 
> want to do with your data.
> 
> Regards
> Petr
> 
> 
> > 
> > Thanks
> > 
> > 
> > From: Petr PIKAL <petr.pikal at precheza.cz>
> > To: azam jaafari <azamjaafari at yahoo.com>
> > Cc: R-help <r-help at r-project.org>
> > Sent: Thursday, September 1, 2011 8:59 AM
> > Subject: Re: [R] convert to grid file
> > 
> > Hi
> > 
> > > 
> > > Hi
> > > 
> > > I computed probability in each cell.
> > > I have:
> > > 
> > >  [99883,] -0.0062412957690
> > >  [99884,] -0.0062412957690
> > >  [99885,] -0.0062412957690
> > >  [99886,] -0.0062412957690
> > >  [99887,] -0.0062412957690
> > >  [99888,] -0.0062412957690
> > >  [99889,]  0.9909126638948
> > >  [99890,]  0.9909126638948
> > >  [99891,]  0.9909126638948
> > >  [99892,]  0.9909126638948
> > >  [99893,]  0.9909126638948
> > >  [99894,]  0.9909126638948
> > >  [99895,]  0.9909126638948
> > >  [99896,]  0.9909126638948
> > >  [99897,]  0.9909126638948
> > >  [99898,]  0.9909126638948
> > >  [99899,]  0.9909126638948
> > >  [99900,]  0.9909126638948
> > >  [99901,]  0.9909126638948
> > >  [99902,]  0.9909126638948
> > >  [99903,]  0.9909126638948
> > > 
> > >  [99999,] -0.0062412957690
> > >  [ reached getOption("max.print") -- omitted 839931 rows ]]
> > > 
> > > How want to convert this matrix to a grid file with 970*960 pixel.
> > 
> > Assuming your object is one column matrix called mat1
> > 
> > You can simply change its dimension
> > 
> > dim(mat) <- c(970, 960)
> > 
> > regards
> > Petr
> > 
> > 
> > 
> > 
> > > 
> > > Thanks alot
> > >    [[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.
> > 
> > 
> 
>



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