Using (x-a) ^ 2 + (y-b) ^ 2 = r ^ 2, the values of a, b and r are known. How do I find x and y values?

2 次查看（过去 30 天）

busra dogru 2019-4-11

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/455759-using-x-a-2-y-b-2-r-2-the-values-of-a-b-and-r-are-known-how-do-i-find-x-and-y-va

评论： Torsten 2019-4-15

I know the values a, b and r. (x-a) ^ 2 + (y-b) ^ 2 = r^2 providing the formula I want to calculate the x and y points . Thank you in advance for your help.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

回答（1 个）

Torsten 2019-4-11

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/455759-using-x-a-2-y-b-2-r-2-the-values-of-a-b-and-r-are-known-how-do-i-find-x-and-y-va#answer_370181

theta = linspace(0,2*pi,100);
x = a + r*cos(theta);
y = b + r*sin(theta);
plot(x,y)

8 个评论
显示 6更早的评论隐藏 6更早的评论

busra dogru 2019-4-14

在 MATLAB Online 中打开

Hello again. I can calculate x and y points with your code. I'm trying to check if these points are in the binary image. I get the following error when I run the following code;

[b, a] = find(newImage);
      A = [a, b];
     [m,n] = size(A);
     
     B = 1;
     t = 1;
        while(t<51)
             for p=1:m
              while(B==1)
                    theta = linspace(0,2*pi);
                    x = A(p,1) + round(t*cos(theta));
                    y = A(p,2) + round(t*sin(theta));
                    x = x';
                    y = y';
                    if x == 0 
                       x = 1;                    
                    end
                    if y == 0
                       y = 1;
                    end
                    B = A(x,y);
                    t = t+1;
             
                end
             end
       
        end
disp(x,y);