angle

问题 My app allows you to draw using a variety of tools. One of them lets you make an angle: you tap three times, then an angle is drawn for you. Unfortunately, it gets really pointy but then rounded again at certain angles for some reason. I'm using CGContextSetLineCap(context, kCGLineCapRound); Here is a picture to exemplify what I'm talking about: Does anyone know what causes this or how to fix it so it is round all the time?? For the most part, all I do is: CGContextMoveToPoint(context, first

问题 Crunch crunch. Using the calculations from Getting End Point in ArcSegment with Start X/Y and Start+Sweep Angles, how could I scrunchify or inflate(-ify) angles. See images below. Green box is original. The yellow lines depict what the scrunchy or inflated start/end angle should become, but red line is if the original angle of start=169, end=293 is maintained on the scrunched or inflated elliptical arcs. I need a way to figure out how to create the new angles of start/end based off the

问题 I have a 2d arrow rotating to always face the a target (the target in this case is the cursor), the pivot is my player character. I need to restrict this arrow to only follow the target if it is inside an angle of the player, an example would be 90 degrees, so it would only follow if the cursor is in the top right part of the screen. I have worked with vector directions and methods such as Vector2D.angle, but they all seem to have some restriction i can't workaround, Vector2D.angles

问题 I'm sorry if this question seems a really basic, but I cannot find a good answer online yet. I'm a little confused with vectors and how to use them in matlab. At the moment I have the following three pair of coordinates (x and y): Person 1, The future location of Person 1 and Person 2. See: The three points in a 2d view Now I want to calculate the angle between "the vector which goes from person 1 to person 2" and "the vector from person 1 to person 1 future". I've found some matlab functions

问题 I am a crystallographer trying to analyse crystals orientations from up to 5000 files. Can Matlab convert angle values in a table that look like this: Into a table that looks like this?: 回答1: Here's a more concrete example based on Lakesh's idea. However, this will handle any amount of rotation. First start off with a base circular image with a strip in the middle. Once you do this, simply run a for loop that stacks all of these rotated images in a grid that resembles the angles seen in your

问题 I'm trying to calculate the intersection between two angle intervals, as in the picture below. Unfortunately, the branch at -pi is making the code much uglier than I have hoped. Here is my first draft. Note that I have not tested this code for correctness, but rather have just gone through the scenarios in my head. As you can see in the function branchify , angle intervals are constrained such that from (p)a1 -> (p)a2 counter-clockwise, the difference is at most pi. In otherwise, the

问题 I've got a longitude and latitude and want to convert this to a quaternion and wondering how I can do this? I want to use this, because I've got an app which projects the earth on a sphere and I want to rotate from one location to another one. Best! 回答1: There's a way to go about this without using matrices or vectors, similar to this numpy implementation. We can think of longitude/latitude as two quaternion rotations composed together. Let's work with a Z-up right-handed coordinate system.

问题 I like radians just as much as the next guy, and typically prefer to use them over degrees, but why do we use radians in programming? To rotate something 180 degrees, you need to rotate it by 3.14159265... . Sure, most languages have some kind of constant for pi, but why do we ever want to use irrational numbers like pi when we can instead use integers, especially for simple programs? We're relying on the computer to say that 3.14159265 is close enough to pi that functions like sine and

问题 I need to determine the angle(s) between two n-dimensional vectors in Python. For example, the input can be two lists like the following: [1,2,3,4] and [6,7,8,9] . 回答1: import math def dotproduct(v1, v2): return sum((a*b) for a, b in zip(v1, v2)) def length(v): return math.sqrt(dotproduct(v, v)) def angle(v1, v2): return math.acos(dotproduct(v1, v2) / (length(v1) * length(v2))) Note : this will fail when the vectors have either the same or the opposite direction. The correct implementation is