Displaying 20 results from an estimated 6000 matches similar to: "How to calculate the perimeter and common border of polygons?"
2011 Feb 17
0
Indentify polygons that are on the border of a shapefile
Dear R users,
I would like to know how to indentify the polygons that are located on the
border of a map (i.e.shapefile).
Do you have any suggestion on how to do it?
Thank you very much,
Leo Monasterio.
[[alternative HTML version deleted]]
2004 Feb 25
2
writing polygons/segments to shapefiles (.shp) or other ArCGIS compatible file
I am not sure a previous e-mail reached the list (no mail aknowledgement from R-boundle etc.). The question was how to write polygon
or segment coordinates into a shapefile set or any other ArcGIS supported format. The library shapefiles seems to do something but
the documentation is a bit beyond of my mind.... and I cannot get the meaning of the functions write**** and its application to the
case
2004 Feb 26
1
writing polygons/segments to shapefiles (.shp) or other A rcGIS compatible file
The main limitation of the shapefiles package that I put together is that it
does not create shapefiles from R objects - rather it only writes shapefiles
that have been read into R and manipulated within the constraints of the
existing file structure. By this I mean that for example you can change the
coordinates of points and write them back out. Or you can add a bunch of
blank columns in the
2023 Nov 20
1
Calculating volume under polygons
Dear all;
I am trying to calculate volume under each polygon of a shapefile according
to a DEM.
when I run the code, it gives me an error as follows.
"
Error in h(simpleError(msg, call)) :
error in evaluating the argument 'x' in selecting a method for function
'addAttrToGeom': sp supports Z dimension only for POINT and MULTIPOINT.
use `st_zm(...)` to coerce to XY dimensions
2006 Nov 30
2
*** caught segfault *** error
Dear R users,
I use R 2.4.0 on an iMac running Mac OS X 10.4.8, with a 2.16GHz
Intel Core 2 Duo and 2GB 667 MHz DDR2 SDRAM.
> sessionInfo()
R version 2.4.0 (2006-10-03)
i386-apple-darwin8.8.1
locale:
es_ES.UTF-8/es_ES.UTF-8/es_ES.UTF-8/C/es_ES.UTF-8/es_ES.UTF-8
attached base packages:
[1] "methods" "stats" "graphics" "grDevices"
2003 Dec 01
1
Re: using shapefile as owin
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
2024 May 17
0
[External] Re: Removing polygons from shapefile of Scotland and Islands
Scotland is the second feature in the UK data, so get it and split this one
MULTIPOLYGON feature into individual POLYGONS
scot = st_cast(the_uk$geometry[2],"POLYGON")
# which is the largest polygon?
which.max(st_area(scot))
[1] 1
# the first one. ok...
plot(scot[[1]]) # mainland
# add the rest of the islands for context, in grey, maybe to show they're
outside our study area:
2010 Apr 01
3
Using GIS data in R
I have a simple problem: I need to load a ERSI shapefile of US states
and check whether or not a set of points are within the boundary of
these states. I have the shapefile, I have the coordinates but I'm
having a great deal of difficulty bringing the two together. The
problem is the various GIS packages for R do not play well with each
other. sp, shapefiles, maptools, etc all use different
2013 Feb 14
1
Clip a contour with shapefile while using contourplot
Hi, I have done the interpolation for my data and I was able to create the
contours in multipanel with the help of Pascal. Now, I want to clip the
contour with the shapefile. I want only the portion of contour to be
displayed which falls inside the boundary of the shapefile.
The data mydata.csv can be found on
https://www.dropbox.com/s/khi7nv0160hi68p/mydata.csv
The data for shapefile can be
2017 Jun 01
0
[spatstat] Convert shapefile to pixel image
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 <-
2023 Dec 06
2
Volume of polygon
Dear all;
I am trying to calculate the volume of a polygon shapefile according to a
DEM raster. I have provided some codes at the end of this email.I dont know
if the codes are correct or not. Following this, I have another question
too.
I want to know if the volume of the reservoir rises or doubles, what would
be the elevation?
I would be more than happy if anyone could help me.
Sincerely
"
2017 Jun 01
3
[spatstat] Convert shapefile to pixel image
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
2006 Mar 21
3
transform shapefiles in UTM to lat/long
Dear all:
I have a shapefile in UTM coordinate system and I would like to transform it
to Lat/Log coordinates (WSG84). The package PBSmapping contains function
convUL to transform between the two coordinate systems when data is in the
form of a data frame with attributes specifying the coordinate system.
However, when shapefiles are imported using function read.shape (package
maptools), a list
2005 Feb 09
1
FW: Drawing maps of UK
Hi Guys
Thanks for this! As I am a beginner, I bet I'm running into some really
basic problems. Using the example from the Map2poly function in
maptools:
try <- read.shape("euadmll.shp")
mappolys <- Map2poly(try)
# this produces 14 warnings() of the type:
# 1: level 2 circularity at 62 in: .mtlbuild(.mtafters(r1), rD) # etc #
14: From next release, default hole handling
2009 Aug 30
1
Trying to rename spatial pts data frame slot that isn't a slot()
Dear List,
I am analyzing the home range area of fish and seem to have lost the individuals ID names during my manipulations, and can't find out how to rename them. I calculated the MCP of the fish using mcp() in Adehabitat. MCP's were converted to spatial points data frame and exported to qGIS for manipulations. At this point the ID names were lost. I brought the manipulated
2009 Aug 14
1
extract data from shapefiles
I'm hoping that someone could guide me in how to extract data from shapefiles. I want to extract data from a shapefile (classed as "SpatialPolygonsDataFrame") and more specifically, the data is contained within the slot called "coords" from the class "polygons" within this file and despite my best efforts (and much reading!), I'm at a lost.
Many thanks,
Kate
2006 Aug 09
1
data.frame to shape
Hi all,
I have a simple question:
I have a data.frame like this:
id x y
1 50 1647685 4815259
2 50 1647546 4815196
3 50 1647454 4815294
4 50 1647405 4815347
5 50 1647292 4815552
6 50 1647737 4815410
7 74 1647555 4815201
8 74 1647464 4815023
9 74 1646970 4815129
10 74 1646895 4815264
11 74 1646762 4815513
and I'd like to trasform it with the "convert.to.shapefile"
2005 Sep 09
2
shapefiles manipulations ??
cheers ,
I need help in shapefile manipulations. I have two shapefiles of my country Cameroon.
The first contain 10 provinces and each province contains a certain number of administratives units. I dont have ESRI Arc view. I want to add a admistrative unit of the center province to the map with 10 province.
Is it possible to to take a peace of shapefile and combining it to another ?
Thanks !
2023 Dec 06
2
Volume of polygon
The volume of a polygon = 0. Polyhedra have volumes.
This may be irrelevant, but if the lake is cylindrical == constant cross
sectional area at all depths, then height doubles when the volume does and
vice versa. Otherwise you have to know how area varies with height or use
more sensible approximations thereto.
Cheers,
Bert
On Tue, Dec 5, 2023, 20:13 javad bayat <j.bayat194 at
2023 Dec 06
1
Volume of polygon
Hi,
As already mentioned, this is a great topic for R-sig-geo, where you'd
probably get specialist answers like the lake morphology package
https://cran.r-project.org/web/packages/lakemorpho/index.html which is
explicitly designed for this kind of question.
Sarah
On Tue, Dec 5, 2023 at 11:13?PM javad bayat <j.bayat194 at gmail.com> wrote:
>
> Dear all;
> I am trying to