similar to: polygon overlapping

Hi there, I want to integrate a function over an irregular polygon. Is there any function which can implement this easily? Otherwise, I am thinking of divide the polygon into very small rectangles and use "adapt" to approximate it. Do you have any suggestions to get the fine division? Any advice is appreciated. Haiyong

In R's maptools package, is there a built-in function to test if a given point is "inside" a given polygon on the map? The map was loaded from an ESRI Shapefile. The point's latitude and longitude are known. Thank you! Aleks -- ------------------------ Aleksandr Andreev Fulbright Fellow Graduate School of Management St Petersburg State University

Dear R-users, Suppose I have the following x-y coordinates which give the boundaries of a polygon: > x <- c(5,4,5,9,6,6,4,7,10,7,10,4,10) > y <- c(6,3,2,6,3,7,5,4,4,7, 5,4, 6) I would like to plot the following graph: > plot(x,y) > ord <- c(7,12,2,3,5,8,9,11,13,4,10,6,1) > polygon(x[ord],y[ord]) How I can obtain the above ordering (in the example an anti-clockwise

I have a list of bounds for a series of polygons. I do understand the formula to determine whether point i is within polygon X (X[x1] < i[x] & X[x2] > i[x] & X[y1] < i[y] & X[y2] > i[y]), and I can apply this throughout the dataset. However, this naive algorithm doesn't scale very well. The data set contains 10,000 points consisting of (n,e) pairs where I'm

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:

Hello, I just want to ask if there is any function that can convert decimal number to binary vector. Thanks a lot. Haiyong

Dear R users, I'm trying to extract from a given matrix (GROUP) the coordinates of the vertices of the different groups (i.e. 3, 7, 1 . . .) to plot the polygons to delineate the area in which each group "wins" and colour it diferentially. I can make a simple point plot, but I would like to add polygons with full colored area. The example is with a 5x5 matrix, but I'm working

Hello, I am a beginner of R. I want to plot the vectors Y vs. X where X has continuous interger values. How can I use the name of each element as the tick label? Thanks a lot! Haiyong

Sorry, I did not make my question clear. Since I have a point theme with many points, some of them may clump together. the problems here are: 1. how to find clumps in a point theme? 2. the convex-hull extension I found only deal with all the points in a theme at each time? how to make each convex hull around each point clump automatically? Thanks. Xiaohua On 5/12/06, Bob Booth <bbooth

My sincerest apologies, as this is a very elementary problem, but I have searched through archives and FAQs and on the web, and I am at the end of my own resources. I need to do analysis of a spatial point process occuring with four counties, using spatstat. I've had no trouble importing the shapefiles, but I can't seem to figure out what I need to do in order to use the boundary as an

I'm making some illustrations and it would be convenient to automatically shade the overlapping portions of circles. These illustrations are for Social Choice theory, a field in political science and economics. I've wrestled together some examples so you can see what I mean, but have not mastered the "color overlapping sections" problem (as you will see):

Hi, I seek to identify those points in/outside a multidimensional convex hull (geometry::convhulln). Any suggestions? Background just in case I'm going down a really wrong road: Given an observed data set with one dependent/observed variable (Y) and multiple (3 to 10) independent/design variables (X1, X2, ...) I want to increase the number of points by interpolating. I'm using

Dear R-helpers, an rgl-ers in particular, what is the easiest way to plot a section of a plane in 3D, that is given by the xyz coordinates of the outline? Suppose I have a polygon - which I know for sure is a set of coordinates on the same plane. One method I found is to use surf.tri from the geometry package, and then plot the triangles with rgl.triangles. This method is not perfect though,

Dear all, 1. How can I compute the intersecting area between 2 polygons ? 2. I have polygons with coordinates in decimal degrees (i.e. 13 deg 30 min = 13.5 decimal degrees). I want to compute their area and get the results in square meters or square kiometers. Can anyone give me a conversion coefficient or a pointer where I can find this information (sorry for this off topic question) ? Thanks

In Germany the Unemployment Agency uses a sectioning of the german map that is different from the usual Administrative Boundaries. Some demographic data are available in Administrative Boundaries only, some in Unemployment Boundaries only. I would like to generate estimates in one boundary system of data availabe in the other boundary system, and would appreciate advice concerning the following

Hello, I am trying to draw a convex-polygon (envelope) connecting the outer points (of a particular class) in a scatter plot [which I want to do to illustrate the range of a particular type of samples in an ordination plot]. Is there any function to plot this kind of polygon? Kind regards Zlatko Petrin

Hello; Please coud you advise me of a simple way to select points (x,y coordinates) that fall within a polygon. I've got a set of polygons, each one defined by an arbitrary number of points, and several points inside each polygon. I know this is simple with a GIS, but I'd rather do it inside R. Thanks and best regards, Javier -----

Hello, I have a distribution dataset for species consisting of xy coordinates at the 1km resolution, with only presence data. So a simplified example of a species distribution might be: y <- rbind(as.integer(rnorm(100,50,20)), as.integer(rnorm(200,100,30)), as.integer(rnorm(100,180,15))) x <- rbind(as.integer(rnorm(200,50,20)), as.integer(rnorm(200,100,20)), as.integer(rnorm(100,200,15)))

Dear all, I am a total beginner in R, so sorry if this is the wrong place. I am using R 2.10.1 on a Mac (Mac OS 10.6.2). I have this small dataset : growth sugar 75 C 72 C 73 C 61 F 67 F 64 F 62 S 63 S I have no problem reading the table, or getting the summary, but if I try boxplot(growth~sugar, ylab="growth", xlab="sugar", data=Dataset), I have the following error :

[Please CC me for all replies, since I am not currently subscribed to the list.] Hi all, I have the following problem/question: Imagine you have a two- dimensional plot, and you want to select a number of points, around which you could draw a polygon. The points of the polygon are defined by clicking in the graphics window (locator()/identify()), all points inside the polygon are