coordinates

What exactly are eye space coordinates?

由 五迷三道 提交于 2019-11-27 00:04:15
问题 As I am learning OpenGL I often stumble upon so-called eye space coordinates. If I am right, you typically have three matrices. Model matrix, view matrix and projection matrix. Though I am not entirely sure how the mathematics behind that works, I do know that the convert coordinates to world space, view space and screen space. But where is the eye space, and which matrices do I need to convert something to eye space? 回答1: Perhaps the following illustration showing the relationship between

Detecting whether a GPS coordinate falls within a polygon on a map

由 非 Y 不嫁゛ 提交于 2019-11-26 23:59:45
问题 As stated in the title, the goal is to have a way for detecting whether a given GPS coordinate falls inside a polygon or not. The polygon itself can be either convex or concave. It's defined as a set of edge vectors and a known point within that polygon. Each edge vector is further defined by four coordinates which are the latitudes and longitudes of respective tip points and a bearing relative to the starting point. There are a couple of questions similar to this one here on StackOverflow

Polygon Touch detection Google Map API V2

由 情到浓时终转凉″ 提交于 2019-11-26 22:35:13
I'm trying to figure out how best to do this, I have a map with one Polygon drawn on it. Since it doesn't seem as though the Google Maps API V2 has a touch detection on a Polygon. I was wonder if it is possible to detect whether the touch point is inside the Polygon? If so then how, my main goal is to outline a state on a map and when the user taps that state it will show more details inside a custom view. As of now I am able to capture the MapOnClick of the map but when the user taps inside the Polygon I want the polygon.getID() set on the Toast . I am a newbie so I apologize if I am not

Calculating the angle between two lines without having to calculate the slope? (Java)

由 不想你离开。 提交于 2019-11-26 22:05:52
I have two Lines: L1 and L2. I want to calculate the angle between the two lines. L1 has points: {(x1, y1), (x2, y2)} and L2 has points: {(x3, y3), (x4, y4)} . How can I calculate the angle formed between these two lines, without having to calculate the slopes? The problem I am currently having is that sometimes I have horizontal lines (lines along the x-axis) and the following formula fails (divide by zero exception): arctan((m1 - m2) / (1 - (m1 * m2))) where m1 and m2 are the slopes of line 1 and line 2 respectively. Is there a formula/algorithm that can calculate the angles between the two

Facebook FQL: Get checkins within range

由 对着背影说爱祢 提交于 2019-11-26 21:41:08
问题 Is there a way to use FQL to select all my friends Checkins that are in range of a specified location? I can use FQL to return my friends checkin coords: https://api.facebook.com/method/fql.query?access_token={0}&query=SELECT coords FROM checkin WHERE author_uid IN (SELECT uid2 FROM friend WHERE uid1 = me()) but how can I add to the above query to do something like... Where coords Within 10 miles of [(New York City, NY) | (long, lat) | (user.current_location)] Any help would be greatly

ggplot2 polar plot arrows

由 旧城冷巷雨未停 提交于 2019-11-26 21:01:36
问题 I can use ggplot2 easily to draw a graph like below: In fact, for my data, it is like below: degree value 1 120 0.50 2 30 0.20 3 -120 0.20 4 60 0.50 5 150 0.40 6 -90 0.14 7 -60 0.50 8 0 0.60 The first column is the degree (from -180 to 180 or from 0 to 360), the second column is the corresponding values. So I want to draw a graph point from (0,0) to each my data point with arrow but with a circular coordinate as below: (source: matrixlab-examples.com) I try to use follow code: base <- ggplot

Implementation of parallel coordinates? [closed]

由 两盒软妹~` 提交于 2019-11-26 20:00:05
问题 I want to implement parallel coordinates for my muldimensional result. Does anyone have a good link to its implementation in matlab or R? Furthermore, are there any suggestions regarding the best tool to use for producing the parallel coordinates? 回答1: R solution lattice package comes with R and includes parallel function: parallel(~iris[1:4] | Species, iris) ggplot2 is also your friend here: D <- data.frame(Gain = rnorm(20), Trader = factor(LETTERS[1:4]), Day = factor(rep(1:5, each = 4)))

How to perform bilinear interpolation in Python

由 人走茶凉 提交于 2019-11-26 19:52:07
问题 I would like to perform blinear interpolation using python. Example gps point for which I want to interpolate height is: B = 54.4786674627 L = 17.0470721369 using four adjacent points with known coordinates and height values: n = [(54.5, 17.041667, 31.993), (54.5, 17.083333, 31.911), (54.458333, 17.041667, 31.945), (54.458333, 17.083333, 31.866)] z01 z11 z z00 z10 and here's my primitive attempt: import math z00 = n[0][2] z01 = n[1][2] z10 = n[2][2] z11 = n[3][2] c = 0.016667 #grid spacing x0

Function to calculate distance between two coordinates

由 别来无恙 提交于 2019-11-26 19:22:24
I'm currently using the function below and it doesn't work properly. According to Google Maps, the distance between these coordinates (from 59.3293371,13.4877472 to 59.3225525,13.4619422 ) are 2.2 kilometres while the function returns 1.6 kilometres. How can I make this function return the correct distance? function getDistanceFromLatLonInKm(lat1, lon1, lat2, lon2) { var R = 6371; // Radius of the earth in km var dLat = deg2rad(lat2-lat1); // deg2rad below var dLon = deg2rad(lon2-lon1); var a = Math.sin(dLat/2) * Math.sin(dLat/2) + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.sin

iPhone current user location coordinates showing as (0,0)

由 拟墨画扇 提交于 2019-11-26 18:24:36
问题 I'm trying to get the users current latitude and longitude with this viewDidLoad method. The resulting map is correctly indicating the current location however the NSLog consistently shows: 2009-09-19 16:45:29.765 Mapper[671:207] user latitude = 0.000000 2009-09-19 16:45:29.772 Mapper[671:207] user longitude = 0.000000 Anyone know what I am missing here? Thanks in advance for your help! - (void)viewDidLoad { [super viewDidLoad]; [mapView setMapType:MKMapTypeStandard]; [mapView setZoomEnabled
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