Plotting maps - Revision history

Wbuytaert at 08:57, 7 August 2008

2008-08-07T08:57:14Z

Wbuytaert at 18:12, 3 August 2008

2008-08-03T18:12:06Z

Wbuytaert at 04:32, 5 May 2008

2008-05-05T04:32:00Z

Wbuytaert at 04:28, 5 May 2008

2008-05-05T04:28:20Z

Wbuytaert at 04:28, 5 May 2008

2008-05-05T04:28:12Z

Wbuytaert at 10:02, 24 January 2008

2008-01-24T10:02:46Z

Wbuytaert at 09:29, 22 January 2008

2008-01-22T09:29:26Z

Wbuytaert at 17:53, 21 January 2008

2008-01-21T17:53:33Z

New page

I decided to give up on plotting nice maps with [http://grass.itc.it grass]. The ps.map function is very powerful, but hard to remember for my not-so-frequent use. R has great plotting capabilities, and of course it does maps. It has an easy [http://cran.r-project.org/src/contrib/Descriptions/spgrass6.html grass interface]. What else do you want (importing other GIS formats? Try [http://cran.r-project.org/src/contrib/Descriptions/rgdal.html rgdal]). Plotting GIS data is very nicely implemented in the [http://cran.r-project.org/src/contrib/Descriptions/sp.html sp] package, part of the [http://r-spatial.sourceforge.net/ spatial data in R] project, but getting your plot the way you want is quite challenging. Here's what I came up with:

library(spgrass6)
library(lattice)
paute <- rast.get6("paute_z")
colours <- topo.colors(1000) # if you want pretty topographic colours
colours <- gray(c(rep(100,10),100:15)/100) # for greyscale colours
trellis.par.set(sp.theme(regions=list(col = colours)))
scale = list("SpatialPolygonsRescale", layout.scale.bar(height=0.1), offset = c(690000,9735000), scale = 20000, fill=c("transparent","black"))
text1 = list("sp.text", c(690000,9740000), "0")
text2 = list("sp.text", c(710000,9740000), "20 km")
arrow = list("SpatialPolygonsRescale", layout.north.arrow(type=1), offset = c(698000,9720000), scale = 10000)
spplot(paute,draw = T, colorkey=list(space="right", height=0.5), cuts=127,
scales=list(draw=T), sp.layout=list(scale,text1,text2,arrow))

Good to know:
* cuts defines the number of colour intervals. The default is 15 and that's not really nice for continuous DEM images
* the colorkey options are part of levelplot {lattice} and is quite customizable

--[[User:Wbuytaert|Wbuytaert]] 17:53, 21 January 2008 (UTC)

@@ Line 9: / Line 9: @@
 ==Required packages==
-spgrass6 reads data from the GRASS database, use rgdal for other formats. sp implements spplot, and lattice is used to define the colours (trells.par.set).
+spgrass6 reads data from the GRASS database, use rgdal for other formats. sp implements spplot, and lattice is used to define the colours (trellis.par.set).
-    library(sp)
+    library(maptools)
     library(spgrass6)
     library(lattice)
@@ Line 17: / Line 17: @@
 ==Plotting a map==
-   #direct import from GRASS, use readGDAL() for other formats
+  # read the DEM and the vectors (for importing other formats see the rgdal package)
-   paute <- rast.get6("paute_DEM")
+  spplot(paute_DEM,draw = T, colorkey=list(space="right", height=0.5), cuts=127,
+     scales=list(draw=T), sp.layout=list(scale,text1,text2,arrow,rivers,limits))
 Good to know:

@@ Line 1: / Line 1: @@
 [[Category:Projects]]
 [[Category:Hydrology in R]]
 ==Introduction==

@@ Line 2: / Line 2: @@
 [[Category:Hydrology in R]]
-I decided to give up on plotting nice maps with [http://grass.itc.it grass]. The ps.map function is very powerful, but hard to remember for my not-so-frequent use. R has great plotting capabilities, and of course it does maps. It has an easy [http://cran.r-project.org/src/contrib/Descriptions/spgrass6.html grass interface]. What else do you want (importing other GIS formats? Try [http://cran.r-project.org/src/contrib/Descriptions/rgdal.html rgdal]). Plotting GIS data is very nicely implemented in the [http://cran.r-project.org/src/contrib/Descriptions/sp.html sp] package, part of the [http://r-spatial.sourceforge.net/ spatial data in R] project, but getting your plot the way you want is quite challenging. Here's what I came up with:
+==Introduction==
         library(spgrass6)
@@ Line 21: / Line 27: @@
 * the ''colorkey'' options are part of levelplot {lattice} and are quite customizable
-The result looks like this:
+==Results==
 [[Image:map_paute.png]]

← Older revision		Revision as of 10:02, 24 January 2008
Line 1:		Line 1:
		+	[[Category:Projects]]
		+	[[Category:Hydrology in R]]
		+
	I decided to give up on plotting nice maps with [http://grass.itc.it grass]. The ps.map function is very powerful, but hard to remember for my not-so-frequent use. R has great plotting capabilities, and of course it does maps. It has an easy [http://cran.r-project.org/src/contrib/Descriptions/spgrass6.html grass interface]. What else do you want (importing other GIS formats? Try [http://cran.r-project.org/src/contrib/Descriptions/rgdal.html rgdal]). Plotting GIS data is very nicely implemented in the [http://cran.r-project.org/src/contrib/Descriptions/sp.html sp] package, part of the [http://r-spatial.sourceforge.net/ spatial data in R] project, but getting your plot the way you want is quite challenging. Here's what I came up with:		I decided to give up on plotting nice maps with [http://grass.itc.it grass]. The ps.map function is very powerful, but hard to remember for my not-so-frequent use. R has great plotting capabilities, and of course it does maps. It has an easy [http://cran.r-project.org/src/contrib/Descriptions/spgrass6.html grass interface]. What else do you want (importing other GIS formats? Try [http://cran.r-project.org/src/contrib/Descriptions/rgdal.html rgdal]). Plotting GIS data is very nicely implemented in the [http://cran.r-project.org/src/contrib/Descriptions/sp.html sp] package, part of the [http://r-spatial.sourceforge.net/ spatial data in R] project, but getting your plot the way you want is quite challenging. Here's what I came up with:

@@ Line 3: / Line 3: @@
 ==Introduction==
-I decided to give up on plotting nice maps with [http://grass.itc.it grass]. The ps.map function is very powerful, but hard to remember for my not-so-frequent use. R has great plotting capabilities, and of course it does maps. It has an easy [http://cran.r-project.org/src/contrib/Descriptions/spgrass6.html grass interface]. What else do you want (importing other GIS formats? Try [http://cran.r-project.org/src/contrib/Descriptions/rgdal.html rgdal]). Plotting GIS data is very nicely implemented in the [http://cran.r-project.org/src/contrib/Descriptions/sp.html sp] package, part of the [http://r-spatial.sourceforge.net/ spatial data in R] project, but getting your plot the way you want is quite challenging.
+R can plot very nice maps. I decided to give up plotting maps in [http://grass.itc.it grass]. The ps.map function is very powerful, but hard to remember for my not-so-frequent use. I use the [http://cran.r-project.org/src/contrib/Descriptions/spgrass6.html grass interface] but R imports very many [http://www.gdal.org/formats_list.html raster] and [http://www.gdal.org/ogr/ogr_formats.html vector] formats via the [http://cran.r-project.org/src/contrib/Descriptions/rgdal.html rgdal] package.
 ==Required packages==
-spgrass6 reads data from the GRASS database. Sp implements spplot and lattice is used to define the colours (trells.par.set).
+spgrass6 reads data from the GRASS database, use rgdal for other formats. sp implements spplot, and lattice is used to define the colours (trells.par.set).
     library(sp)
@@ Line 13: / Line 15: @@
     library(lattice)
-==Procedure==
+==Plotting a map==
-       paute <- rast.get6("paute_z")
+   #direct import from GRASS, use readGDAL() for other formats
-       colours <- topo.colors(1000) # if you want pretty topographic colours
-       colours <- gray(c(rep(100,10),100:15)/100) # for greyscale colours
+   paute <- rast.get6("paute_DEM")
-       trellis.par.set(sp.theme(regions=list(col = colours)))
-       scale = list("SpatialPolygonsRescale", layout.scale.bar(height=0.1), offset = c(690000,9735000), scale = 20000, fill=c("transparent","black"))
+   # set some nice topographic colours, if you want dull greyscale colors, use:
-       text1 = list("sp.text", c(690000,9740000), "0")
+   # colours <- gray(c(rep(100,10),100:15)/100)
-       text2 = list("sp.text", c(710000,9740000), "20 km")
-       arrow = list("SpatialPolygonsRescale", layout.north.arrow(type=1), offset = c(698000,9720000), scale = 10000)
+   colours <- topo.colors(1000)
-       spplot(paute,draw = T, colorkey=list(space="right", height=0.5), cuts=127,
+   trellis.par.set(sp.theme(regions=list(col = colours)))
-              scales=list(draw=T), sp.layout=list(scale,text1,text2,arrow))
 Good to know:

@@ Line 15: / Line 15: @@
 Good to know:
-* cuts defines the number of colour intervals. The default is 15 and that's not really nice for continuous DEM images
+* ''cuts'' defines the number of colour intervals. The default is 15 and that's not really nice for continuous DEM images
-* the colorkey options are part of levelplot {lattice} and is quite customizable
+* the ''colorkey'' options are part of levelplot {lattice} and are quite customizable
 --[[User:Wbuytaert|Wbuytaert]] 17:53, 21 January 2008 (UTC)