great-circle

问题 I was looking for a geographical library for python. I need to be able to do the following: Get the distance between 2 points (in meters) using Great-circle distance (not liner distance calculation) Check if a point is inside a polygon Perform 1 and 2 couple of thousands times per seconds At start I've looked at this post: Python module for storing and querying geographical coordinates and started to use geopy. I've encountered 2 problems: Geopy doesn't support polygons High CPU usage of

问题 I was looking for a geographical library for python. I need to be able to do the following: Get the distance between 2 points (in meters) using Great-circle distance (not liner distance calculation) Check if a point is inside a polygon Perform 1 and 2 couple of thousands times per seconds At start I've looked at this post: Python module for storing and querying geographical coordinates and started to use geopy. I've encountered 2 problems: Geopy doesn't support polygons High CPU usage of

问题 Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 3 years ago . Improve this question I'm looking for a Java library that is capable of performing spatial calculations on sets of lat/lon data. Here are some of the functions that I'm looking for: Calculate the Great Circle distance between two points Determine if a point lies within a simple closed

问题 MySQL OpenGIS CROSSES doesn't seem to work for me: SET @ls = 'LineString(1 1, 2 2, 3 3)'; SET @xx = 'LineString(0 2, 10 2)'; # SELECT AsText(EndPoint(GeomFromText(@ls))); select crosses(GeomFromText(@ls), GeomFromText(@xx)) returns 0 - expected 1 How would I rewrite this as a MySQL function? Bonus points for using lat, lon and spherical projection (and maybe the Great Circle.) PS I can't create tags and I have lost my old login: Useful tags would be: MySQL OpenGIS CROSSES greatcircle lat lon

问题 I'm trying to build something like this http://flowingdata.com/2011/05/11/how-to-map-connections-with-great-circles/ but with my own data in csv files. The code runs well if I use the same csv files as the author, but with mine , this is what I get Code library(maps) library(geosphere) map("world") xlim <- c(-180.00, 180.00) ylim <- c(-90.00, 90.00) map("world", col = "#f2f2f2", fill = TRUE, bg = "white", lwd = 0.05,xlim = xlim, ylim = ylim) airports <- read.csv("/Users/shabnam/Desktop

问题 I am using Version 4 of the D3 Library and am, to this point, unable to draw connecting lines between points on a Symbol Map. In the example, from an earlier version of the library, drawing connecting lines is accomplished with this code: // calculate the Great Arc between each pair of points var arc = d3.geo.greatArc() .source(function(d) { return locationByAirport[d.source]; }) .target(function(d) { return locationByAirport[d.target]; }); [snip] // Draw the Great Arcs on the Chart. g

问题 I'm setting up a small program to take 2 geographical coordinates from a user and then calculate the distance between them(taking into account the curvature of the earth). So I looked up wikipedia on what the formula is here. I basically set up my python function based on that and this is what I came up with: def geocalc(start_lat, start_long, end_lat, end_long): start_lat = math.radians(start_lat) start_long = math.radians(start_long) end_lat = math.radians(end_long) end_long = math.radians

问题 So I have a table with a bunch of different addresses in it. I need a proc that will select the addresses in that table that are within a specified distance in miles from the passed in lat/long values. So example of my table: - messageId - lat (float) - long (float) Proc is passing in another lat/long pair (both float s as well) as well as an int (miles) I found this http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=81360 to calculate the actual formula but I can't figure out to modify it in

问题 I am familiar with the formula to calculate the Great Circle Distance between two points. i.e. <?php $theta = $lon1 - $lon2; $dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) + cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta)); $dist = acos($dist); $dist = rad2deg($dist); //convert degrees to distance depending on units desired ?> What I need though, is the reverse of this. Given a starting point, a distance, and a simple cardinal NSEW direction, to calculate the position of

问题 I've taken some of the things I learned in a Flowing Data great circle mapping tutorial and combined them with code linked in the comments to prevent weird things from happening when R plots trans-equatorial great circles. That gives me this: airports <- read.csv("/home/geoff/Desktop/DissertationData/airports.csv", header=TRUE) flights <- read.csv("/home/geoff/Desktop/DissertationData/ATL.csv", header=TRUE, as.is=TRUE) library(maps) library(geosphere) checkDateLine <- function(l){ n<-0 k<