How can I plot a 2D array using polar coordinates?

16 次查看（过去 30 天）
Jiong Yang
Jiong Yang 2020-5-4
评论： Ava 2023-11-3
Hi,
I have a 2D array, with each row representing polar angle 'theta' and each column representing 'value' at paticular radius.
When I use 'imagesc', I got this (x-axis is the radius axis, y-axis is the theta axis)
How can I plot this array in polar coordinates?
  2 个评论
Image Analyst
Image Analyst 2020-5-5
How many rows and columns, and what is the formula relating row number to angle, and column number to radius?
Jiong Yang
Jiong Yang 2020-5-5
Attached is the data. It has 157 rows and 112 columns.
I got this array by calculation. Each row equals 0.01 theta, and the total polar angle is pi/2. Each column equals 0.01 in radius.
Thank you very much.

请先登录，再进行评论。

请先登录，再回答此问题。

回答（1 个）

darova
darova 2020-5-5
Convert your data to cartesian system of coordinates
A = xlsread('data.xlsx');
%%
t = linspace(0,pi/2,size(A,1)); % create angle
r = (1:size(A,2))*0.01; % create radius
[T,R] = ndgrid(t,r); % 2d matrices
[X,Y] = pol2cart(T,R); % polar to cartesian
surf(X,Y,A,'edgecolor','none')
view(2)
  2 个评论
Jiong Yang
Jiong Yang 2020-5-6
Thank you, Darova. I tried something else and got it done. Thank you anyway!
Ava
Ava 2023-11-3
Hi @Jiong Yang, may I ask how you solved this? I am working on an plotting ozone levels over Antarctica with a 2D array and would like to "imagesc" the data but with the rows and columns representing angle and radius.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Polar 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