distance

问题 I'm developing an android app for my college that helps students track the current location of the college bus and also give them an estimated time when the bus might reach them. As of now I get the current location of the bus(via a device present on the bus) and the location of the student. I'm stuck at the point where I have to find the distance between the two GPS co-ordinates. I have to find the distance between the bus and the student "along a specific route" (i.e the path the bus takes)

问题 I have table with data from GPS, e.g.: Latitude , Longitude , Time , UserId How to aggregate total distance in specified time frame summing all distances by all points (ordered by time) and group data by user? Thanks 回答1: If you are using SQL Server, you might be interested in using the geography data type so you can request the database using the dedicated method and geographical index. The geography data type is available since SQL Server 2008, you can more information right here: http:/

问题 I am having an issue calculating distance using the Location.distanceTo method. private class MyLocationOverlay1 extends MyLocationOverlay { @Override public void drawMyLocation(Canvas canvas, MapView mapView, Location lastFix, GeoPoint myLocation, long when) super.drawMyLocation(canvas,mapView,lastFix,myLocation,when); Location bLocation = new Location("reverseGeocoded"); bLocation.setLatitude(FindList.gpslat); // Value = 3.294391E7 bLocation.setLongitude(FindList.gpslong); // Value = -9

问题 I have this problem in calculating Jaccard Distance for Sets (Bit-Vectors): p1 = 10111; p2 = 10011. Size of intersection = 3; (How could we find it out?) Size of union = 4, (How could we find it out?) Jaccard similarity = (intersection/union) = 3/4. Jaccard Distance = 1 – (Jaccard similarity) = (1-3/4) = 1/4. But I don't understand how could we find out the "intersection" and "union" of the two vectors. Please help me. Thanks alot. 回答1: Size of intersection = 3; (How could we find it out?)

问题 I have this problem in calculating Jaccard Distance for Sets (Bit-Vectors): p1 = 10111; p2 = 10011. Size of intersection = 3; (How could we find it out?) Size of union = 4, (How could we find it out?) Jaccard similarity = (intersection/union) = 3/4. Jaccard Distance = 1 – (Jaccard similarity) = (1-3/4) = 1/4. But I don't understand how could we find out the "intersection" and "union" of the two vectors. Please help me. Thanks alot. 回答1: Size of intersection = 3; (How could we find it out?)

问题 I have 2 lists with X,Y coordinates of points. List 1 contains more points than list 2. The task is to find pairs of points in a way that the overall euclidean distance is minimized. I have a working code, but i don't know if this is the best way and I would like to get hint what I can improve for result (better algorithm to find the minimum ) or speed, because the list are about 2000 elements each. The round in the sample vectors is implemented to get also points with same distances. With

问题 I guess you have all tried "Google Places" in Maps. This is a list of POI close to you. I really would like to do the same feature in my application with a list of GPS coordinates, but that seem really complicated. Making the listview with the distance and the little arrow is very easy, but I cannot understand how to update this list and the arrow everytime the user move his phone. For now I have a static listview. I would like to know if someone succeed to create such a listview. Thank a lot

问题 I would like to have a function where I can input a radius value and have said function spit out the area for that size circle. The catch is I want it to do so for integer based coordinates only. I was told elsewhere to look at Gauss's circle problem , which looks to be exactly what I'm interested in, but I don't really understand the math behind it (assuming it is actually accurate in calculating what I'm wanting). As a side note, I currently use a modified circle drawing algorithm which

问题 I keep getting the following error when trying to run metaMDS() from the vegan package: my_mds <- vegan::metaMDS(df_species, distance="bray", k=2, trymax=1000, autotransform=TRUE) Error in .C("veg_distance", x = as.double(x), nr = N, nc = ncol(x), d = double(N * : "veg_distance" not available for .C() for package "vegan" I have tried: 1. searching online for this error - which yields zero results 2. reducing the size of my data frame to 17 rows and 12 columns 3. clearing all packages from

问题 I want to calculate the driving distance between two locations [the user's specified locations], before user starts the driving. I used many formulas and getDistanceFrom in CLLocation also, but I am not able to get the perfect the driving distance between those locations. There is much difference in actual and calculated distance. Please help me to calculate the driving distance between two locations. How can I use Google Maps API to calculate the driving distance ? I have already use the