Project coordinates based on projection in the first file to the projection given in the second

Description

Project coordinates based on projection in the first Models3-formatted file to the projection given in the second Models3-formatted file.

Usage

project.M3.1.to.M3.2(x, y, from.file, to.file, units, ...)

Arguments

Details

This function calls get.proj.info.M3 which reads the projection information (using the package ncdf4) and transforms it to strings that are understood by functions in rgdal. Package rgdal provides the R interface to GDAL (Geospatial Data Abstraction Library, http://www.gdal.org).

Value

A list containing the elements coords and units. The element coords contains a matrix of coordinates using projection in to.file. The element units contains the units of the coordinates, which are the same as those specified for input x and y.

Warning

This function assumes the projections in from.file and to.file are Lambert conic conformal or polar stereographic.

Author(s)

Jenise Swall

References

http://www.gdal.org

See Also

project.lonlat.to.M3, project.M3.to.lonlat, get.proj.info.M3

Examples

## Find the path to a demo file with lambert conic conformal projection.
lcc.file <- system.file("extdata/ozone_lcc.ncf", package="M3")

## Read in the ozone for July 4 for eastern U.S.
lcc.oz <- get.M3.var(file=lcc.file, var="O3",
                      lcol=90, ucol=130, lrow=30, urow=80,
                      ldatetime=as.Date("2001-07-04"),
                      udatetime=as.Date("2001-07-04"))

## Get the cell centers for this subset.
east.ctrs <- expand.grid(lcc.oz$x.cell.ctr, lcc.oz$y.cell.ctr)
plot(east.ctrs, cex=0.3, xlab="x", ylab="y")

## Find map lines on this projection, superplot.
lcc.state.bds <- get.map.lines.M3.proj(file=lcc.file)$coords
lines(lcc.state.bds, col="darkblue")


## Find the path to a demo file with polar stereographic projection.
polar.file <- system.file("extdata/surfinfo_polar.ncf", package="M3")

## Put the cell centers from the subsetted ozone data on this polar
## stereographic projection.
polar.oz <- project.M3.1.to.M3.2(east.ctrs[,1], east.ctrs[,2],
                                 from.file=lcc.file,
                                 to.file=polar.file,
                                 units=lcc.oz$hz.units)

## Plot the cells centers and boundary lines on the polar
## stereographic projection.
dev.new()
plot(polar.oz$coords)
polar.state.bds <- get.map.lines.M3.proj(file=polar.file)$coords
lines(polar.state.bds, col="darkblue")

Results

R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(M3)
Loading required package: ncdf4
Loading required package: rgdal
Loading required package: sp
rgdal: version: 1.1-10, (SVN revision 622)
 Geospatial Data Abstraction Library extensions to R successfully loaded
 Loaded GDAL runtime: GDAL 1.11.3, released 2015/09/16
 Path to GDAL shared files: /usr/share/gdal/1.11
 Loaded PROJ.4 runtime: Rel. 4.9.2, 08 September 2015, [PJ_VERSION: 492]
 Path to PROJ.4 shared files: (autodetected)
 Linking to sp version: 1.2-3 
Loading required package: maps

 # maps v3.1: updated 'world': all lakes moved to separate new #
 # 'lakes' database. Type '?world' or 'news(package="maps")'.  #


Loading required package: mapdata
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/M3/project.M3.1.to.M3.2.Rd_%03d_medium.png", width=480, height=480)
> ### Name: project.M3.1.to.M3.2
> ### Title: Project coordinates based on projection in the first file to the
> ###   projection given in the second
> ### Aliases: project.M3.1.to.M3.2
> 
> ### ** Examples
> 
> ## Find the path to a demo file with lambert conic conformal projection.
> lcc.file <- system.file("extdata/ozone_lcc.ncf", package="M3")
> 
> ## Read in the ozone for July 4 for eastern U.S.
> lcc.oz <- get.M3.var(file=lcc.file, var="O3",
+                       lcol=90, ucol=130, lrow=30, urow=80,
+                       ldatetime=as.Date("2001-07-04"),
+                       udatetime=as.Date("2001-07-04"))
> 
> ## Get the cell centers for this subset.
> east.ctrs <- expand.grid(lcc.oz$x.cell.ctr, lcc.oz$y.cell.ctr)
> plot(east.ctrs, cex=0.3, xlab="x", ylab="y")
> 
> ## Find map lines on this projection, superplot.
> lcc.state.bds <- get.map.lines.M3.proj(file=lcc.file)$coords
> lines(lcc.state.bds, col="darkblue")
> 
> 
> ## Find the path to a demo file with polar stereographic projection.
> polar.file <- system.file("extdata/surfinfo_polar.ncf", package="M3")
> 
> ## Put the cell centers from the subsetted ozone data on this polar
> ## stereographic projection.
> polar.oz <- project.M3.1.to.M3.2(east.ctrs[,1], east.ctrs[,2],
+                                  from.file=lcc.file,
+                                  to.file=polar.file,
+                                  units=lcc.oz$hz.units)
> 
> ## Plot the cells centers and boundary lines on the polar
> ## stereographic projection.
> dev.new()
Error in dev.new() : no suitable unused file name for pdf()
Execution halted