spiral

问题 I'm trying to figure out how to do a pixel (color) search from the center and out, in a spiral shape.. Not like the normal "left to right pixel search". So far i've made some simple x-y searches. Using standard PIL. But it was to slow. as the result always seems to be closer to the center (of the image) in my case. The thing is that it's not a square image, so the center position(s) can be 2 or more pixels (not A center, but "two"+ pixels centerd), this is where I "loose it".. Can you peeps

来源： https://stackoverflow.com/questions/63810793/filling-the-area-between-archimedes-spyrals-with-interpolated-colours-matplotl

来源： https://stackoverflow.com/questions/63810793/filling-the-area-between-archimedes-spyrals-with-interpolated-colours-matplotl

问题 I tried to solve Leetcode Problem 54 - spiral and got stuck in empty vector input. the question is about spiral list. input is 2d vector and output should be vector list which written by spiral direction. Input: [ [1, 2, 3, 4], [5, 6, 7, 8], [9,10,11,12] ] Output: [1,2,3,4,8,12,11,10,9,5,6,7] problem is when input is empty list. Input: [] it produces runtime error. another testcases passed except empty input like [] . It seems no runtime error during testing in my mac OSX terminal, but

问题 I want to find if a point (x,y)where x,y integers satisfy the spiral square. (0,0) (0,1) (1,1) (1,2) (0,2) (-1,2) (-2,2) (-2,1) (-2,0) ans so on..... How do I do it? I want the logic for a java or c++ function. 回答1: Here is some pseudocode logic: Start with x=0, y=0, dist=0, direction=1 Loop x += (++dist * direction) WritePoint(x,y) y += (++dist * direction) WritePoint(x,y) direction *= -1 LoopEnd Take it from there. 回答2: Do this operation: (operator)(operation)(amount) where operator

问题 How do you draw a swirl in R ? I am trying to plot a list of numbers 1:100 and every 7th number assign it a factor '1' all others just '0' . I also have a vector of TRUE or FALSE . How do I plot a swirl of these numbers and highlight every seventh number ? Trying to see if I can tighten or loosen the swirl (theta) to align the 7th numbers. The following code I used to create the data. I used two different functions just to see which vector would work best. A logical vector or a vector of "1"

问题 Given a number x, insert elements 1 to x^2 in a matrix spirally. e.g. For x = 3, matrix looks like [[1,2,3],[8,9,4],[7,6,5]]. For this I've written following snippet. However, I'm getting o/p as [[7,9,5],[7,9,5],[7,9,5]] while(t<=b && l<=r){ System.out.print(t+" "+b+" "+l+" "+r+"\n"); if(dir==0){ for(int i = l;i<=r;i++){ arr.get(t).set(i,x); x++; } t++; }else if(dir==1){ for(int i = t;i<=b;i++){ arr.get(i).set(r,x); x++; } r--; }else if(dir==2){ for(int i = r;i>=l;i--){ arr.get(b).set(i,x); x

问题 I want to draw a shape at center that starts from the center of the panel and keeps expanding out in circular shape like in the picture link below : https://www.dropbox.com/s/lnxi1be8uogn2zx/20140320_124537.jpg but i am having difficulty with the center shape , its like it doesnt show up at all on the panel. Here is the class i wrote for the shapes package graphics.test; import java.awt.Graphics; import javax.swing.JPanel; public class DrawPanel extends JPanel { public void paintComponent

问题 I have an Archimedean spiral determined by the parametric equations x = r t * cos(t) and y = r t * sin(t) . I need to place n points equidistantly along the spiral. The exact definition of equidistant doesn't matter too much - it only has to be approximate. Using just r , t and n as parameters, how can I calculate the coordinates of each equidistant point? 回答1: You want to place points equidistantly corresponding to arc length. Arc length for Archimedean spiral (formula 4) is rather complex s

问题 Does anybody have a PHP (or other language) script for drawing a spiral. A simple (Archimedean spiral) would be just fine. Of course the principle is simple but coding it in SVG or GD would take some time, so I wonder if somebody has one ready :-) 回答1: See this page: Using GD (imagearc) and PHP to draw spirals (Listing 27.3) 来源： https://stackoverflow.com/questions/2546370/php-script-to-draw-a-spiral