find values within limits

2 次查看（过去 30 天）
Duncan
Duncan 2014-8-26
评论： Image Analyst 2014-8-26
I have the equation of a circle:
(x - a)^2 + (y - b)^2 - r^2 = 0
a, b and r are known values and I would like to find the values of x and y from a predetermined coordinate matrix which satisfies the equation.
example: a = 2, b = 2, r = 2
A = 1 2
1 3
2 4
4 2
The coding to do this is:
a = 2; b = 2; r = 2;
B = A((A(:,1)-a).^2+(A(:,2)-b).^2==r^2,:);
then the last two values would satisfy and hence display 2,4 and 4,2.
What I would like to know is how this code would change if i set limits. Say I want to display only the value that is within the limits of +/-1 for a & b.
i.e. it would only display 2,4

请先登录，再回答此问题。

回答（1 个）

Image Analyst
Image Analyst 2014-8-26
Do you want to create a ring/torus/annulus? If so, see the FAQ: http://matlab.wikia.com/wiki/FAQ#How_do_I_create_an_ring.3F
  4 个评论
显示 2更早的评论
Duncan
Duncan 2014-8-26
The "2nd coordinate value" can be found in matrix "A". what i mean by 'limit' is to set a limit on the coordinate points to be displayed that is within matrix A
Image Analyst
Image Analyst 2014-8-26
Maybe I'm just dense but that means nothing to me, but a diagram would help me immensely.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Contour Plots 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by