math

问题 I am making an HTML5 and Javascript platform game. At this moment all blocks of the map are handled as squares. This method is "ugly" when the block is not an exact square/rectangle. Check this image I made to get a better understand of my point: Case one: The "bottom bumper" is touching the square that envolves the block so the movement is stopped. Case two: If I use the same method as above, when the players jumps, the movement will be stopped before the "top bumper" even touches the block.

问题 I have an array of 2d vertices and I want to detect if there are any arch or circle shapes in a array. Sometimes the values are not that precise and I need a small range. Here are the values. The 3rd verticle value value remains 0: verticle: -0.014848, -13.2684, 0 angle : 0.141274 verticle: -0.0174556, -4.84519, 0 angle : 90 verticle: 0, 0, 0 angle : 90 verticle: -9.53674e-07, 14.14, 0 angle : 40.7168 verticle: -12.1101, 14.0709, 0 angle : 7.94458 verticle: -12.0996, 10.6442, 0 angle : 0

问题 So this is a bit of a nitty gritty question... I have a time-series signal that has a non-uniform response spectrum that I need to whiten. I do this whitening using a frequency time normalization method, where I incrementally filter my signal between two frequency endpoints, using a constant narrow frequency band (~1/4 the lowest frequency end-member). I then find the envelope that characterizes each one of these narrow bands, and normalize that frequency component. I then rebuild my signal

问题 I have a database-driven web application where the primary keys of all data rows are obfuscated as follows: SHA256(content type + primary key + secret), truncated to the first 8 characters. The content type is a simple word, e.g. "post" or "message" and the secret is a 20-30 char ASCII constant. The result is stored in a separate indexed column for fast DB lookup. How do I calculate the probability of a hash collision in this scenario? I am not a mathematician at all, but a friend claimed

问题 I am trying to make a code for this problem: (Source: https://www.codewars.com/kata/insane-coloured-triangles/train/c) A coloured triangle is created from a row of colours, each of which is red, green or blue. Successive rows, each containing one fewer colour than the last, are generated by considering the two touching colours in the previous row. If these colours are identical, the same colour is used in the new row. If they are different, the missing colour is used in the new row. This is

问题 I am trying to make a code for this problem: (Source: https://www.codewars.com/kata/insane-coloured-triangles/train/c) A coloured triangle is created from a row of colours, each of which is red, green or blue. Successive rows, each containing one fewer colour than the last, are generated by considering the two touching colours in the previous row. If these colours are identical, the same colour is used in the new row. If they are different, the missing colour is used in the new row. This is

问题 I want to randomize a float that so that There is 95% chance to be about 1 There is 0.01% chance to be < 0.1 or > 1.9 It never becomes 0 or 2 Is this possible by using Random.nextFloat() several times for example? A visual illustration of the probability: 回答1: You need to find a function f such that: f is continuous and increasing on [0, 1] f(0) > 0 and f(1) < 2 f(0.01) >= 0.1 and f(0.99) <= 1.9 f(x) is "about 1" for 0.025 <= x <= 0.975 And then just take f(Random.nextDouble()) For example,

问题 I am looking for a solution for the following problem and it just won't work the way I want to. So my goal is to calculate a regression analysis and get the slope, intercept, rvalue, pvalue and stderr for multiple rows (this could go up to 10000). In this example, I have a file with 15 rows. Here are the first two rows: array([ [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24], [ 100, 10, 61, 55, 29, 77, 61, 42, 70, 73, 98, 62, 25, 86, 49, 68, 68, 26, 35

问题 Lets say for each detected face, I have a set of landmarks like this (result from face detection API): "eye_left": { "x": 112.3, "y": 210.3 }, "eye_right": { "x": 217.5, "y": 205.5 }, "nose": { "x": 168.6, "y": 269.7 }, "mouth l": { "x": 119.1, "y": 307.6 }, "mouth_l": { "x": 119.1, "y": 307.6 }, "mouth r": { "x": 215, "y": 302.9 }, "mouth_r": { "x": 215, "y": 302.9 }, "pose": { "roll": -3.71, "yaw": 3.92, "pitch": -6.44 }, "b_ll": { "x": 74.3, "y": 184.6 }, "b_lm": { "x": 103.7, "y": 174.7 }

问题 List the following functions in non-descending order of asymptotic growth rate. If two or more functions have the same asymptotic growth rate then group them together. g1(n) = n g2(n) = n^3 +4n g3(n) = 2n log(base 2) n g4(n) = 2^n g5(n) = 3 ^ (3 * log(base 3) n) g6(n) = 10^n I've been looking through several examples online but I have no idea how to do this, it just seems like a completely foreign concept to me. If anyone could help me, that would be much appreciated. how do I even calculate