similar to: Holding a large number of SEXPs in C++

Dear all, I am currently working with the spatstat package, using windows and pixel images. First: My aim is to transform a shapefile (see attached) into a pixel image. My idea is to start transforming the shapefile into a Spatial Polygon file: x <- readShapeSpatial("200001441.shp") y <- as(x, "SpatialPolygons") z <- as.owin(y) Given z, I want to identify each

On 02/06/17 01:17, Lluis.Hurtado at uv.es wrote: > Dear all, > > I am currently working with the spatstat package, using windows and pixel images. > > First: > > My aim is to transform a shapefile (see attached) into a pixel image. > > My idea is to start transforming the shapefile into a Spatial Polygon file: > > x <-

Dear R-users, I’m currently trying to extract the value of a slot (area) but can’t find out how to do that. >str(overlperc) List of 1 $ :Formal class 'SpatialPolygons' [package "sp"] with 4 slots .. ..@ polygons :List of 1 .. .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots .. .. .. .. ..@ Polygons :List of 1 .. .. .. .. .. ..$

I am trying to rasterize a SpatialPolygon object by a RasterBrick object. The documentation of the raster::rasterize function explicitly says this is allowed. Here's what I am doing # load the raster package library("raster") # create a raster brick object using the example from the brick function documentation b <- brick(system.file("external/rlogo.grd",

I imported the attached tiff file and converted the coordinate system to long lat and graphed it: californiatiff<- readGDAL("california1.tif") proj4string(californiatiff) > rasterprojection <- spTransform(californiatiff, CRS("+proj=longlat") however, when using the plot command for rasterprojection, I get a blob. I can see the outline of the state of california and

Dear Roger, I am trying to use the write.polylistShape() function of maptools for the first time and realize that it handles list of polygons of class 'polylist'. However, it seems that no as.polylist() function exist in the package. The question behind that is: in your opinion, which would be the best way to convert a list of matrix of polygon nodes coordinates into an object of

Dear List, I'm trying to use different R packages for my Teaching Assistantship classes. And I cam out to an (apparently) very simple problem. I would like to retrieve the vertices coordinate of a SpatialPolygon data. I know this is stored in the "coords" slot, but I can't get access to it! I tried to coerce the SpatialPolygon into a data.frame but it doesn't work.

I have an XML file that has within it the coordinates of some polygons that I would like to extract and use in R. The polygons are nested rather deeply. For example, I found by trial and error that I can extract the coordinates of one of them using functions from the XML package: doc <- xmlInternalTreeParse('doc.kml') docroot <- xmlRoot(doc) pgon <-

Hello dear members of R-help and R-core mailing list, I am not sure if this request is a "ticket" that should be filled somewhere outside the mailing list. If so, I apologize for not doing and would like to know where I should have filled it. And to the subject matter: I would like to use a command like this: plot(c(1,8), 1:2, type="n") polygon(1:7, c(2,1,2,NA,2,1,2),

Hello dear members of R-help and R-core mailing list, I am not sure if this request is a "ticket" that should be filled somewhere outside the mailing list. If so, I apologize for not doing and would like to know where I should have filled it. And to the subject matter: I would like to use a command like this: plot(c(1,8), 1:2, type="n") polygon(1:7, c(2,1,2,NA,2,1,2),

Objective: Determine if a set of x and y-latitude points are inside of a polygon using R. Lets say I have 9 polygons. Where I have labeled the polygons to be checked from 1-9. The problem I?m running into is running the point.in.polygon to check if those points are in one of several polygons, as my code overwrites the result. To accomplish this I am using the R-built in function called

Am just feeling my way into the grid library, and cannot figure out how to define the plot limits. 3/5 of the example polygons below plot in the default 0-1 range viewport. But when I try to redefine the viewport the polygons plot in the same places. I also get the same result without employing push/pop. (As you can see from the scale I'm trying to introduce, I want to plot map polygons.)

The angle is not based on the polygon edges, but it can seem that way if you do not use the asp=1 argument in your plot. Try this example, > plot(1:10, 1:10, type='n') > x <- c(1, 3, 5, 3) > y <- c(3, 5, 3, 1) > polygon(x, y, angle=0, density=10) > polygon(x, y + 4.5, angle=45, density=10) > polygon(x + 4.5, y + 4.5, angle=90, density=10) > polygon(x + 4.5, y,

Filling polygons with lines is a throwback to the time when the height of quality graphics was the mechanical pen plotter (a device that used a pen in a mechanical arm to draw the plot on a piece of paper). Computing and printing technology has advanced quite a bit from that day, so you may want to reconsider why you want polygons filled with lines instead of just a solid color (and I consider

Hi, I'm trying to use grid.polygon() to plot several polygons at once, with a view to putting coloured polygons beneath a curve. I'm struggling just to get the grid.polygon to plot anything # PLOT SOME POINTS x <- 1:100 y <- 1:100*0.5 + 3 plot(x, y, pch = ".") # PLOT 2 POLYGONS library(grid) grid.polygon(x = c(20, 20, 40, 40, 40, 40, 60, 60), y =

Dear all, We are analysing some survey data and we are not sure if we are using the correct syntax for our design. The population of interest is a set of 4416 polygons with different sizes ranging from 0.003 to 45.6 ha, 7460 ha in total. Each polygon has a binary attribute (presence/absence) and we want to estimate the probability of presence in the population. We used sampling with replacement

I am trying to use the angle option in polygon to create polygons filled with horizontal and vertical lines. The polygons I am crating are irregular and it the angle function appears to set the angle of the shading perpendicular to the polygon sides rather than perpendicular to the axes. Is there any way to set the angle relative to the axes rather than relative to the polygon sides?

Tena koe Simon plot(1:10, 1:10, type='n') polygon(c(2,3,6,8), c(2,5,5,3), density=20, angle=90) polygon(c(2,3,6,8), 5+c(2,5,5,3), density=20, angle=0) I don't understand your problem. Perhaps if you "provide[d] commented, minimal, self-contained, reproducible code" it would help. HTH .... Peter Alspach -----Original Message----- From: R-help [mailto:r-help-bounces at

Dear R-helpers, thanks for yesterday's speeding-up tip. Here is my next query: I have lots of polygons (not necessarily convex ones, and they never have holes) given by x,y coordinates. I want to get the polygon that is the union of these polygons. This is my current method, but I am hoping there is a faster method (up to thousands of polygons, each with ca. 40 xy points). Example:

Hi, I'm looking the best way to fill irregular polygons with patterns, Something like the function grid.pattern do, but my case is with irregular polygons. Whit this script I can get it, but I'm looking for an "elegant" solution.. library(grid) grid.polygon(x=c(0.2, 0.8, 0.6, 0.6, 0.8, 0.2), y=c(0.2, 0.2, 0.3, 0.5, 0.7,0.7), gp=gpar(fill="grey",