Does anyone know the proper interpretation of the accuracy measurements returned by getAccuracy()? For instance, are they calculated as: Circular Error Probability (meaning, if i understand correctly, radius of a 50% confidence circle)? Radius of 95% confidence circle? something else? In addition, what are the actual calculations tha...
I am terribly annoyed by the inaccuracy of the intrinsic trig functions in the CLR. It is well know that Math.Sin(Math.PI)=0.00000000000000012246063538223773 instead of 0. Something similar happens with Math.Cos(Math.PI/2). But when I am doing a long series of calculations that on special cases evaluate to Math.Sin(Math.PI/2+x)-M...
The source data : static double[] felix = new double[] { 0.003027523, 0.002012256, -0.001369238, -0.001737660, -0.001647287, 0.000275154, 0.002017238, 0.001372621, 0.000274148, -0.000913576, 0.001920263, 0.001186456, -0.000364631, 0.000638337, 0.000182266, -0.001275626, -0.000821093, 0.001186998, -0.000455996, -0.0...
Hi, I'm trying to find a way to calculate the area of a polygon using lat long coordinates in a Flex 3 site. Hong007 on Google Maps for Flash group was cool enough to post the following function: private function GetPolygonArea (polygon : Polygon):Number { var nVer : int = polygon.getOuterVertexCount(); ...
I'm trying to get my current location and show it on a map. Class com.google.android.maps.MyLocationOverlay.MyLocationOverlay does most of the work for you. But it's coming back with a very coarse result that's off by a couple of clicks. I'm listening for onAccuracyChanged() but that never gets called. How can I get a more accurate...
the following are listed in CLLocation.h but from my experience they are deceiving names- possibly originally thought up to serve two purposes, 1. to test the accuracy of the location returned, but also 2. to set how hard the location manager works, specifically what is enabled (gps (how many sat channels), how hard the wifi works, trian...
Hello, here is my problem : I have a mobile app, and I want to give the user some information depending on their position ( think something like FourSquare ). But how to make sure the user position is real ? I mean let's say the client uses a request to the server via http : http://www.myserver.com/getdata?lat=X&long=Y ...
Hi everyone, as I am developing for iPhone, I've just bought an iPhone 4 to test my application which needs to measure the coordinates of my location. I don't have any Internet (3GS, GPRS or whatever...) on my iPhone and the problem is: 1) Without internet I get a 1744m horizontal accuracy, and that's very bad. (I've also tested the acc...
As programmers, most (if not all of us) know that floating point numbers have a tendency to not be very accurate. I know that this problem can't be avoided entirely, but I am wondering if there are any certain practices, patterns, etc. that can be used to at least reduce floating point errors. Thanks in advance. ...
While learning about precision in floating point arithmetic and different methods to avoid it (using a conjugate, taylor series,...) books frequently mention the subtraction of two very similar numbers or one large and one small number as the biggest cause of error. How come it is only subtraction that causes this and not addition? As I ...
Maybe i got my head around this wrong, after stfw i could not find any info on this. When the geolocation api returns your position with latitute, longitude and accuracy (p.coords.accuracy), does the accuracy parameter return diameter or radius of your position? For instance, if accuracy of my position is 24 meters, does that mean i coul...
Hi, I'm trying to calculate the lag between two signals in Python using cross correlation. The two signals are almost identical except for a very small timelag. I've tried numpy.correlate and scipy.convolve (alot faster) and both works relatively well but gives a small error. I'm starting to suspect that the error is the result of Pytho...
Hi, I'm writting and small app to get the course from the gps. I've tested it outdoor with my car, and newLocation.course always gives even numbers, 0, 2, 4, ... 180, 182, ... 356, 358. I've set distancefilter to none and accuracy to best. ¿Is this a known issue of corelocation?. Am I doing something wrong? Here's is the code (void)l...
Hi everybody, I'd like to develop an iPhone app that must that locate the user in a museum then popups some useful information about the sculpture he is looking at. Thus, these questions came to my mind: How accurate are the longitude and the latitude values ? Because I want to give to each place in the museum this couple of values s...