math

问题 I'm making a game where there should be a robot throwing ball-shaped objects at another robot. The balls thrown should fly in the shape of a symmetrical arc. Pretty sure the math-word for this is a parabola. Both robots are on the x axis. How can I implement such a thing in my game? I tried different approaches, none worked. The current system of moving things in my game, is like so: Every object has x and y co-ordinates (variables), and dx and dy variables. Every object has a move() method,

问题 Suppose the user inputs an infix expression as a string? What could be the easiest ( By easiest I mean the shortes t) way to evaluate the result of that expression using C language? Probable ways are converting it to a postfix then by using stacks.But its rather a long process. Is there any way of using functions such as atoi() or eval() that could make the job easier? 回答1: Certainly the most instructive way (and possibly even the easiest, once you know how) is to learn how to write your own

问题 I'm working with two unit vectors but not sure how to calculate this. I need it so that if they point in the same direction the answer is 1, opposite directions the answer is 0, perpendicular (either up or down) the answer is 0.5, etc. Examples: For two vectors (1,0) and (-1,0) (so, opposite vectors), the answer I get is 0. For two vectors (1,0) and (1/sqrt(2),1/sqrt(2)) (so, the unit vector pointing at a 45 degree angle) I get 0.25. For two vectors (0,1) and (-1,0) (so, perpendicular vectors

问题 While looking at various methods for point-in-triangle testing (2D case), I found that the method which uses barycentric coordinates is the most used one. Here is a StackOverflow answer which explains it. Why is this method the most preferred one? It probably has to do with doing less calculations, but what about numerical stability? Is this algorithm better suited than say, the "same side" technique, for cases in which the point is particularly near the border? 回答1: If you solve it: p = p0 +

问题 While looking at various methods for point-in-triangle testing (2D case), I found that the method which uses barycentric coordinates is the most used one. Here is a StackOverflow answer which explains it. Why is this method the most preferred one? It probably has to do with doing less calculations, but what about numerical stability? Is this algorithm better suited than say, the "same side" technique, for cases in which the point is particularly near the border? 回答1: If you solve it: p = p0 +

问题 While looking at various methods for point-in-triangle testing (2D case), I found that the method which uses barycentric coordinates is the most used one. Here is a StackOverflow answer which explains it. Why is this method the most preferred one? It probably has to do with doing less calculations, but what about numerical stability? Is this algorithm better suited than say, the "same side" technique, for cases in which the point is particularly near the border? 回答1: If you solve it: p = p0 +

问题 While looking at various methods for point-in-triangle testing (2D case), I found that the method which uses barycentric coordinates is the most used one. Here is a StackOverflow answer which explains it. Why is this method the most preferred one? It probably has to do with doing less calculations, but what about numerical stability? Is this algorithm better suited than say, the "same side" technique, for cases in which the point is particularly near the border? 回答1: If you solve it: p = p0 +

问题 How can I plot a skewed normal distribution in R, given the number of cases, the mean, standard deviation, median and the MAD. A example would be that I have 1'196 cases, were the mean cost is 6'389, the standard deviation 5'158, the median 4'930 and the MAD 1'366. And we know that the billed case always cost something, so the cost must always be positive. The best answer to this problem I could find is from https://math.stackexchange.com/a/17995/54064 and recommends the usage of the sn

问题 I want to draw line from unityUI. (i dont want to use Line Renderer in unity). So I figured out the coding below, but my problem is the line sizes are not constant. public class MyUILineRenderer : Graphic { public Vector2[] pointPos; public float[] angles; public MyUIGridRenderer gridRenderer; public Vector2Int gridSize = new Vector2Int(1, 1); public float lineThickness = 0.5f; public float width; public float height; public float unitWidth; public float unitHeight; public float angleHelp;

问题 I have an excessively big number (1500+) digits and I need to find 2 ** that number modulo 1_000_000_000 so I wrote this python: n = 1 return_value = 2 while n < To_the_power_of: return_value *= 2 return_value = return_value % 1_000_000_000 n += 1 This returns the correct value for smaller values, but takes too long for bigger values. If the number is modulo 10 then you get this pattern which could be used. 2 ** 1 modulo 10 = 2 2 ** 2 modulo 10 = 4 2 ** 3 modulo 10 = 8 2 ** 4 modulo 10 = 6 2