latitude-longitude

问题 Is there a ST_Distance_Sphere, ST_Distance_Spheroid equivalent function in MySQL's GeoSpatial Support? If not, any way to emulate this? What is the metric used in return type of GLength (length of the LineString)? The manual for GLength says that GLength() is a nonstandard name. It corresponds to the OpenGIS Length() function. But I couldn't find any Docs for OpenGIS Length(). All I found was for ST_Length are they the same? Also for accuracy do I need to specify the SRID(4326)? How Do I do

问题 I have an App with a TextView that finds your location and when you move, the value in TextView changes. I want to know what can I do in order to register the first location and then look for the location 5 min after. For example: min 0 LAT 000000 LONG 000000 ( SAVE IT ) min 5 LAT 1111111 LONG 111111 if min0 == min 5 ... To sum up, I want to compare 2 strings (lat & long at the beginning) and lat & long after 5 minutes. Any suggestion will be appreciated. 回答1: This Link should serve your

问题 So I managed to implement the google map with a dragable marker on my website. The only problem I have now is that I don't know how to save the location of where the marker is put the last time. So if a user drags the marker 4 times, I want to save the location (latitude and longitude) of the 4th time only. This is what I have so far (This is the working code without the code to save the location): <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>

问题 I am getting the latitude and longitude from GPS device. They look like 21081686N,079030977E If I manually convert them to 21°08'16.86"N, 79°03'09.77"E and check on Google maps, the location is almost correct. How do I convert these values in java and convert them to decimal accurately? Any JAVA libraries? Thanks, 回答1: You shouldn't need a library, but rather just break up the strings into their component parts. Perhaps this will help. Please note I'm not a Java programmer so this syntax

问题 I have a regular expression that I want to match a latitude/longitude pair in a variety of fashions, e.g. 123 34 42 -123* 34' 42" 123* 34' 42" +123* 34' 42" 45* 12' 22"N 45 12' 22"S 90:00:00.0N I want to be able to match these in a pair such that 90:00:00.0N 180:00:00.0E is a latitude/longitude pair. or 45* 12' 22"N 46* 12' 22"E is a latitude/longitude pair (1 degree by 1 degree cell). or 123* 34' 42" 124* 34' 42" is a latitude/longitude pair etc Using the below regular expression, when I

问题 The documentation says that if pyEpehm is given a TLE and a time it will return the following. However, I'm having no luck converting the returned 'sublat' and 'sublon' to ECEF XYZ and back to LLA coordinates to verify. When I convert back the longitude is preserved but the latitude is off by about ~20 degrees for different tests. I am using functions that are verified with GPS ephemeris and I am very confident that the LLA to ECEF and back works for those parameters. Something else is going

问题 I am using the below destination [BMAnalytics].[dbo].[EUACTIVESTORES] And it has columns [Store No] [Lat] [Long] Can I use these columns to self Join the [Store No] so I have each combination of Store to Store listed in two columns, called 'Source' & 'Target' And then in a third column is it possible to calculate the distance between the two? I have used the below previously but this only works for one single point to point, DECLARE @source geography = 'POINT(0 51.5)' DECLARE @target

问题 I'm looking for a list of timezones with polygon lat/lng information. I want to build a tool that I can punch in a lat/lng and spit out a timezone. Basically the same thing that Geonames and EarthTools does except that I don't want to have to make a web service call or depend on a third-party service with request limits. Any suggestions on where I can find this data? 回答1: Look this website. http://www.geonames.org/ Have daily updates 来源： https://stackoverflow.com/questions/6247432/timezone

问题 I need to parse some user submitted strings containing latitudes and longitudes, under Ruby. The result should be given in a double Example: 08º 04' 49'' 09º 13' 12'' Result: 8.080278 9.22 I've looked to both Geokit and GeoRuby but haven't found a solution. Any hint? 回答1: "08° 04' 49'' 09° 13' 12''".gsub(/(\d+)° (\d+)' (\d+)''/) do $1.to_f + $2.to_f/60 + $3.to_f/3600 end #=> "8.08027777777778 9.22" Edit: or to get the result as an array of floats: "08° 04' 49'' 09° 13' 12''".scan(/(\d+)° (\d+

问题 I have a matrix with shape (64,17) correspond to time & latitude. I want to take a weighted latitude average, which I know np.average can do because, unlike np.nanmean, which I used to average the longitudes, weights can be used in the arguments. However, np.average doesn't ignore NaN like np.nanmean does, so my first 5 entries of each row are included in the latitude averaging and make the entire time series full of NaN. Is there a way I can take a weighted average without the NaN's being