similar to: Calculating angle of a polyline

Assuming your polyline is defined by two vectors, one for the x coordinates, one for the y coordinates, you can try the following library(NISTunits) polyangles <- function(xV,yV) { stopifnot( (length(xV)==length(yV)) && (length(xV) >= 3)) v <- function(i) { c( xV[i]-xV[i-1], yV[i]-yV[i-1])} vlen <- function(v) { sqrt(sum(v*v)) } lV <- rep(NA_real_,length(xV)) for

A polyline by definition has many angles, so your question is ill-formed. And this is a question about math, not R, so is off topic here. I suggest reading Wikipedia. -- Sent from my phone. Please excuse my brevity. On January 29, 2018 11:10:02 PM PST, javad bayat <j.bayat194 at gmail.com> wrote: >Dear R users >I am trying to find a formula to calculate the angle of a polyline. Is

I like to use complex numbers for 2-dimensional geometry. E.g., > polyAngles2 function (xV, yV) { stopifnot((length(xV) == length(yV)) && (length(xV) >= 3)) z <- complex(re = xV, im = yV) c(NA, diff(Arg(diff(z))), NA) # radians, positive is counter-clockwise } > x <- c(0:3) > y <- c(0,0,1,1) > polyAngles2(x,y) / pi * 180 [1] NA 45 -45 NA Bill

Dear all; I have downloaded meteorology data from " https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=form" as .grib format. It has hourly data of a complete year (every hour of every day of 12 months) and has 6 meteorology parameters. The file has been attached. I am trying to convert it to an excel file that puts every parameter in a separated column.

Dear Bert and Sara; I have searched on the internet and found some way to do this like python. But python is so complicated to me as it needs many steps to be done for reading and converting it. I will try terra package to convert it. On Tue, 25 Jun 2024, 15:15 javad bayat, <j.bayat194 at gmail.com> wrote: > Richard, > Many thanks for your email. > I had attached the grib file to

Richard, Many thanks for your email. I had attached the grib file to the original email to R help team but it seems you did not receive it. Unfortunately, I do not know how to reduce the volume or extract some of the grib file data to send it for you. The file has the volume of 6 Megabyte. I can send it by email. The file has 6 met parameters and Date (day/month/year hour:minute). I want the

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

Might want to post this on R-sig-geo. Might also want to post in plain text format... see below how your message got messed up coming through the mailing list. -- Sent from my phone. Please excuse my brevity. On November 12, 2017 9:58:56 PM PST, Javad Bayat via R-help <r-help at r-project.org> wrote: >I have a shape file as poly line and I want to convert it to polygon.Is >it

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 "

I have a shape file as poly line and I want to convert it to polygon.Is it possible to do that in R?lake <-readShapeLines("./lake_main_utm.shp")proj4string(lake) <- CRS("+proj=utm +zone=39 +datum=WGS84") Sincerely. [[alternative HTML version deleted]]

Attachments CAN NOT be sent to group On Thu, 26 Sep 2024, 21:22 javad bayat, <j.bayat194 at gmail.com> wrote: > Dear Roy, > Sorry for my mistake, I thought I have uploaded the grib file. > I really apologise for that. I will send it on Saturday. > Thank you very much. > > On Thu, 26 Sept 2024, 17:40 Roy Mendelssohn - NOAA Federal, < > roy.mendelssohn at

I'm now inclined to go with 'search for "convert GRIB to CSV". https://confluence.ecmwf.int/display/CKB/How+to+convert+GRIB+to+CSV is the first line. I know that's not an R solution, but using software specifically developed for encoding, decoding, extracting, &c GRIB file by the European Centre for Medium-Range Weather Forecasts and actively maintained, with an example

Hi Javad: I know a lot about reading GRIB files, I work with them all the time. But if you don?t make the file available, or point me to where I can download it, there is not much I can do. Thanks, -Roy > On Sep 25, 2024, at 9:41?PM, javad bayat <j.bayat194 at gmail.com> wrote: > > Dear all; > Many thanks for your responses. Actually it is not completely a GIS file, it

Dear Roy, Sorry for my mistake, I thought I have uploaded the grib file. I really apologise for that. I will send it on Saturday. Thank you very much. On Thu, 26 Sept 2024, 17:40 Roy Mendelssohn - NOAA Federal, < roy.mendelssohn at noaa.gov> wrote: > Hi Javad: > > I know a lot about reading GRIB files, I work with them all the time. > But if you don?t make the file

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

I''m working on a mapstraction implementation modeled after the radius search feature. (http://mapstraction.com/demo-radius.php) I''d like to recognize when the user extends the radius beyond the visible edges of the map and adjust the zoom level. I''m not seeing how to test this when redrawing the circle. I thought maybe I wanted to use polylineCenterAndZoom()

Dear all; Many thanks for your responses. Actually it is not completely a GIS file, it is a data file which stores meteorological data of a specific region. But the site allows downloading with grib format and as I searched to read this type of file in R, I found the Raster Package. In python it is possible to do this using cdsapi and xarray library, but I am not familiar with python. Sincerely

Whoops, sorry, you *did* answer "what went wrong". > param_names <- c("param1", "param2", "param3", "param4", "param5", "param6") > extracted_data <- extract(raster_data, param_names, df = TRUE) #Error in (function (classes, fdef, mtable) : #unable to find an inherited method for function ?extract? for signature

Dear all; Thank you for your reply. David has explained an interesting method. David I have DEM file of the region and I have extracted the xyz data from that. Also I can extract bathymetry data as xyz file. I have calculated the storage (volume) of reservoir at the current elevation. But the method I have used to calculate the volume is different from your method. I have crop DEM by the reservoir

hi all, how can i saving R output to docx or Jpeg format? [[alternative HTML version deleted]]