create circular dot grids

4 次查看(过去 30 天)
I have the plot of the borders of the continents. how can i create circles like those in the picture? I have the latitude and longitude of the central point, the radius of the circumference, which would be a distance, and 10 points that would build the circumference that are 36 degrees apart from each other.

采纳的回答

Simon Chan
Simon Chan 2021-8-16
编辑:Simon Chan 2021-8-16
Use function pol2cart
clear; clc;
separation = 36; % Angle separation
rhoA = 10; % Radius #1, 10 pixels
rhoB = 15; % Radius #2, 15 pixels
num_dot = 360/separation +1; % Total number of points
theta = linspace(-pi,pi,num_dot); % Theta separation
cx = 50; % Your center point, x-coordinates = 50 (example)
cy = 25; % Your center point, y-coordinates = 25 (example)
[xA,yA] = pol2cart(theta,rhoA); % Use pol2cart
[xB,yB] = pol2cart(theta,rhoB); % Use pol2cart
A = zeros(100,100); % Original region, example, size: 100x100
[Ny, Nx]= size(A);
xA_convert = round(cx-xA); % Convert back from polar coordinates
yA_convert = round(cy-yA);
xB_convert = round(cx-xB);
yB_convert = round(cy-yB);
for k = 1:num_dot
A(yA_convert(k),xA_convert(k)) =1; % Put the dots in matrix A (can skip this loop)
A(yB_convert(k),xB_convert(k)) =1;
end
plot(cx,cy,'ro'); % Your center point
hold on
plot(xA_convert,yA_convert,'b+')
plot(xB_convert,yB_convert,'g*')
xlim([0 Nx])
ylim([0 Ny])
  3 个评论
ELISABETTA BILLOTTA
it seems to work but how do I convert the radius in pixels to km? in the sense I have the information of the distance in km, I have to enter the pixel from what I understand.
Thanksss
Simon Chan
Simon Chan 2021-8-17
编辑:Simon Chan 2021-8-17
May use this function: latlon2local

请先登录,再进行评论。

更多回答(0 个)

类别

Help CenterFile Exchange 中查找有关 Line Plots 的更多信息

Community Treasure Hunt

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

Start Hunting!

Translated by